1 //===- LegalizeDAG.cpp - Implement SelectionDAG::Legalize -----------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the SelectionDAG::Legalize method.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/ADT/APFloat.h"
14 #include "llvm/ADT/APInt.h"
15 #include "llvm/ADT/ArrayRef.h"
16 #include "llvm/ADT/SetVector.h"
17 #include "llvm/ADT/SmallPtrSet.h"
18 #include "llvm/ADT/SmallSet.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/Analysis/TargetLibraryInfo.h"
21 #include "llvm/CodeGen/ISDOpcodes.h"
22 #include "llvm/CodeGen/MachineFunction.h"
23 #include "llvm/CodeGen/MachineJumpTableInfo.h"
24 #include "llvm/CodeGen/MachineMemOperand.h"
25 #include "llvm/CodeGen/RuntimeLibcalls.h"
26 #include "llvm/CodeGen/SelectionDAG.h"
27 #include "llvm/CodeGen/SelectionDAGNodes.h"
28 #include "llvm/CodeGen/TargetFrameLowering.h"
29 #include "llvm/CodeGen/TargetLowering.h"
30 #include "llvm/CodeGen/TargetSubtargetInfo.h"
31 #include "llvm/CodeGen/ValueTypes.h"
32 #include "llvm/IR/CallingConv.h"
33 #include "llvm/IR/Constants.h"
34 #include "llvm/IR/DataLayout.h"
35 #include "llvm/IR/DerivedTypes.h"
36 #include "llvm/IR/Function.h"
37 #include "llvm/IR/Metadata.h"
38 #include "llvm/IR/Type.h"
39 #include "llvm/Support/Casting.h"
40 #include "llvm/Support/Compiler.h"
41 #include "llvm/Support/Debug.h"
42 #include "llvm/Support/ErrorHandling.h"
43 #include "llvm/Support/MachineValueType.h"
44 #include "llvm/Support/MathExtras.h"
45 #include "llvm/Support/raw_ostream.h"
46 #include "llvm/Target/TargetMachine.h"
47 #include "llvm/Target/TargetOptions.h"
48 #include <algorithm>
49 #include <cassert>
50 #include <cstdint>
51 #include <tuple>
52 #include <utility>
53 
54 using namespace llvm;
55 
56 #define DEBUG_TYPE "legalizedag"
57 
58 namespace {
59 
60 /// Keeps track of state when getting the sign of a floating-point value as an
61 /// integer.
62 struct FloatSignAsInt {
63   EVT FloatVT;
64   SDValue Chain;
65   SDValue FloatPtr;
66   SDValue IntPtr;
67   MachinePointerInfo IntPointerInfo;
68   MachinePointerInfo FloatPointerInfo;
69   SDValue IntValue;
70   APInt SignMask;
71   uint8_t SignBit;
72 };
73 
74 //===----------------------------------------------------------------------===//
75 /// This takes an arbitrary SelectionDAG as input and
76 /// hacks on it until the target machine can handle it.  This involves
77 /// eliminating value sizes the machine cannot handle (promoting small sizes to
78 /// large sizes or splitting up large values into small values) as well as
79 /// eliminating operations the machine cannot handle.
80 ///
81 /// This code also does a small amount of optimization and recognition of idioms
82 /// as part of its processing.  For example, if a target does not support a
83 /// 'setcc' instruction efficiently, but does support 'brcc' instruction, this
84 /// will attempt merge setcc and brc instructions into brcc's.
85 class SelectionDAGLegalize {
86   const TargetMachine &TM;
87   const TargetLowering &TLI;
88   SelectionDAG &DAG;
89 
90   /// The set of nodes which have already been legalized. We hold a
91   /// reference to it in order to update as necessary on node deletion.
92   SmallPtrSetImpl<SDNode *> &LegalizedNodes;
93 
94   /// A set of all the nodes updated during legalization.
95   SmallSetVector<SDNode *, 16> *UpdatedNodes;
96 
97   EVT getSetCCResultType(EVT VT) const {
98     return TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
99   }
100 
101   // Libcall insertion helpers.
102 
103 public:
104   SelectionDAGLegalize(SelectionDAG &DAG,
105                        SmallPtrSetImpl<SDNode *> &LegalizedNodes,
106                        SmallSetVector<SDNode *, 16> *UpdatedNodes = nullptr)
107       : TM(DAG.getTarget()), TLI(DAG.getTargetLoweringInfo()), DAG(DAG),
108         LegalizedNodes(LegalizedNodes), UpdatedNodes(UpdatedNodes) {}
109 
110   /// Legalizes the given operation.
111   void LegalizeOp(SDNode *Node);
112 
113 private:
114   SDValue OptimizeFloatStore(StoreSDNode *ST);
115 
116   void LegalizeLoadOps(SDNode *Node);
117   void LegalizeStoreOps(SDNode *Node);
118 
119   /// Some targets cannot handle a variable
120   /// insertion index for the INSERT_VECTOR_ELT instruction.  In this case, it
121   /// is necessary to spill the vector being inserted into to memory, perform
122   /// the insert there, and then read the result back.
123   SDValue PerformInsertVectorEltInMemory(SDValue Vec, SDValue Val, SDValue Idx,
124                                          const SDLoc &dl);
125   SDValue ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val, SDValue Idx,
126                                   const SDLoc &dl);
127 
128   /// Return a vector shuffle operation which
129   /// performs the same shuffe in terms of order or result bytes, but on a type
130   /// whose vector element type is narrower than the original shuffle type.
131   /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
132   SDValue ShuffleWithNarrowerEltType(EVT NVT, EVT VT, const SDLoc &dl,
133                                      SDValue N1, SDValue N2,
134                                      ArrayRef<int> Mask) const;
135 
136   bool LegalizeSetCCCondCode(EVT VT, SDValue &LHS, SDValue &RHS, SDValue &CC,
137                              bool &NeedInvert, const SDLoc &dl, SDValue &Chain,
138                              bool IsSignaling = false);
139 
140   SDValue ExpandLibCall(RTLIB::Libcall LC, SDNode *Node, bool isSigned);
141 
142   void ExpandFPLibCall(SDNode *Node, RTLIB::Libcall Call_F32,
143                        RTLIB::Libcall Call_F64, RTLIB::Libcall Call_F80,
144                        RTLIB::Libcall Call_F128,
145                        RTLIB::Libcall Call_PPCF128,
146                        SmallVectorImpl<SDValue> &Results);
147   SDValue ExpandIntLibCall(SDNode *Node, bool isSigned,
148                            RTLIB::Libcall Call_I8,
149                            RTLIB::Libcall Call_I16,
150                            RTLIB::Libcall Call_I32,
151                            RTLIB::Libcall Call_I64,
152                            RTLIB::Libcall Call_I128);
153   void ExpandArgFPLibCall(SDNode *Node,
154                           RTLIB::Libcall Call_F32, RTLIB::Libcall Call_F64,
155                           RTLIB::Libcall Call_F80, RTLIB::Libcall Call_F128,
156                           RTLIB::Libcall Call_PPCF128,
157                           SmallVectorImpl<SDValue> &Results);
158   void ExpandDivRemLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
159   void ExpandSinCosLibCall(SDNode *Node, SmallVectorImpl<SDValue> &Results);
160 
161   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
162                            const SDLoc &dl);
163   SDValue EmitStackConvert(SDValue SrcOp, EVT SlotVT, EVT DestVT,
164                            const SDLoc &dl, SDValue ChainIn);
165   SDValue ExpandBUILD_VECTOR(SDNode *Node);
166   SDValue ExpandSPLAT_VECTOR(SDNode *Node);
167   SDValue ExpandSCALAR_TO_VECTOR(SDNode *Node);
168   void ExpandDYNAMIC_STACKALLOC(SDNode *Node,
169                                 SmallVectorImpl<SDValue> &Results);
170   void getSignAsIntValue(FloatSignAsInt &State, const SDLoc &DL,
171                          SDValue Value) const;
172   SDValue modifySignAsInt(const FloatSignAsInt &State, const SDLoc &DL,
173                           SDValue NewIntValue) const;
174   SDValue ExpandFCOPYSIGN(SDNode *Node) const;
175   SDValue ExpandFABS(SDNode *Node) const;
176   SDValue ExpandFNEG(SDNode *Node) const;
177   SDValue ExpandLegalINT_TO_FP(SDNode *Node, SDValue &Chain);
178   void PromoteLegalINT_TO_FP(SDNode *N, const SDLoc &dl,
179                              SmallVectorImpl<SDValue> &Results);
180   void PromoteLegalFP_TO_INT(SDNode *N, const SDLoc &dl,
181                              SmallVectorImpl<SDValue> &Results);
182 
183   SDValue ExpandBITREVERSE(SDValue Op, const SDLoc &dl);
184   SDValue ExpandBSWAP(SDValue Op, const SDLoc &dl);
185   SDValue ExpandPARITY(SDValue Op, const SDLoc &dl);
186 
187   SDValue ExpandExtractFromVectorThroughStack(SDValue Op);
188   SDValue ExpandInsertToVectorThroughStack(SDValue Op);
189   SDValue ExpandVectorBuildThroughStack(SDNode* Node);
190 
191   SDValue ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP);
192   SDValue ExpandConstant(ConstantSDNode *CP);
193 
194   // if ExpandNode returns false, LegalizeOp falls back to ConvertNodeToLibcall
195   bool ExpandNode(SDNode *Node);
196   void ConvertNodeToLibcall(SDNode *Node);
197   void PromoteNode(SDNode *Node);
198 
199 public:
200   // Node replacement helpers
201 
202   void ReplacedNode(SDNode *N) {
203     LegalizedNodes.erase(N);
204     if (UpdatedNodes)
205       UpdatedNodes->insert(N);
206   }
207 
208   void ReplaceNode(SDNode *Old, SDNode *New) {
209     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
210                dbgs() << "     with:      "; New->dump(&DAG));
211 
212     assert(Old->getNumValues() == New->getNumValues() &&
213            "Replacing one node with another that produces a different number "
214            "of values!");
215     DAG.ReplaceAllUsesWith(Old, New);
216     if (UpdatedNodes)
217       UpdatedNodes->insert(New);
218     ReplacedNode(Old);
219   }
220 
221   void ReplaceNode(SDValue Old, SDValue New) {
222     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
223                dbgs() << "     with:      "; New->dump(&DAG));
224 
225     DAG.ReplaceAllUsesWith(Old, New);
226     if (UpdatedNodes)
227       UpdatedNodes->insert(New.getNode());
228     ReplacedNode(Old.getNode());
229   }
230 
231   void ReplaceNode(SDNode *Old, const SDValue *New) {
232     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG));
233 
234     DAG.ReplaceAllUsesWith(Old, New);
235     for (unsigned i = 0, e = Old->getNumValues(); i != e; ++i) {
236       LLVM_DEBUG(dbgs() << (i == 0 ? "     with:      " : "      and:      ");
237                  New[i]->dump(&DAG));
238       if (UpdatedNodes)
239         UpdatedNodes->insert(New[i].getNode());
240     }
241     ReplacedNode(Old);
242   }
243 
244   void ReplaceNodeWithValue(SDValue Old, SDValue New) {
245     LLVM_DEBUG(dbgs() << " ... replacing: "; Old->dump(&DAG);
246                dbgs() << "     with:      "; New->dump(&DAG));
247 
248     DAG.ReplaceAllUsesOfValueWith(Old, New);
249     if (UpdatedNodes)
250       UpdatedNodes->insert(New.getNode());
251     ReplacedNode(Old.getNode());
252   }
253 };
254 
255 } // end anonymous namespace
256 
257 /// Return a vector shuffle operation which
258 /// performs the same shuffle in terms of order or result bytes, but on a type
259 /// whose vector element type is narrower than the original shuffle type.
260 /// e.g. <v4i32> <0, 1, 0, 1> -> v8i16 <0, 1, 2, 3, 0, 1, 2, 3>
261 SDValue SelectionDAGLegalize::ShuffleWithNarrowerEltType(
262     EVT NVT, EVT VT, const SDLoc &dl, SDValue N1, SDValue N2,
263     ArrayRef<int> Mask) const {
264   unsigned NumMaskElts = VT.getVectorNumElements();
265   unsigned NumDestElts = NVT.getVectorNumElements();
266   unsigned NumEltsGrowth = NumDestElts / NumMaskElts;
267 
268   assert(NumEltsGrowth && "Cannot promote to vector type with fewer elts!");
269 
270   if (NumEltsGrowth == 1)
271     return DAG.getVectorShuffle(NVT, dl, N1, N2, Mask);
272 
273   SmallVector<int, 8> NewMask;
274   for (unsigned i = 0; i != NumMaskElts; ++i) {
275     int Idx = Mask[i];
276     for (unsigned j = 0; j != NumEltsGrowth; ++j) {
277       if (Idx < 0)
278         NewMask.push_back(-1);
279       else
280         NewMask.push_back(Idx * NumEltsGrowth + j);
281     }
282   }
283   assert(NewMask.size() == NumDestElts && "Non-integer NumEltsGrowth?");
284   assert(TLI.isShuffleMaskLegal(NewMask, NVT) && "Shuffle not legal?");
285   return DAG.getVectorShuffle(NVT, dl, N1, N2, NewMask);
286 }
287 
288 /// Expands the ConstantFP node to an integer constant or
289 /// a load from the constant pool.
290 SDValue
291 SelectionDAGLegalize::ExpandConstantFP(ConstantFPSDNode *CFP, bool UseCP) {
292   bool Extend = false;
293   SDLoc dl(CFP);
294 
295   // If a FP immediate is precise when represented as a float and if the
296   // target can do an extending load from float to double, we put it into
297   // the constant pool as a float, even if it's is statically typed as a
298   // double.  This shrinks FP constants and canonicalizes them for targets where
299   // an FP extending load is the same cost as a normal load (such as on the x87
300   // fp stack or PPC FP unit).
301   EVT VT = CFP->getValueType(0);
302   ConstantFP *LLVMC = const_cast<ConstantFP*>(CFP->getConstantFPValue());
303   if (!UseCP) {
304     assert((VT == MVT::f64 || VT == MVT::f32) && "Invalid type expansion");
305     return DAG.getConstant(LLVMC->getValueAPF().bitcastToAPInt(), dl,
306                            (VT == MVT::f64) ? MVT::i64 : MVT::i32);
307   }
308 
309   APFloat APF = CFP->getValueAPF();
310   EVT OrigVT = VT;
311   EVT SVT = VT;
312 
313   // We don't want to shrink SNaNs. Converting the SNaN back to its real type
314   // can cause it to be changed into a QNaN on some platforms (e.g. on SystemZ).
315   if (!APF.isSignaling()) {
316     while (SVT != MVT::f32 && SVT != MVT::f16) {
317       SVT = (MVT::SimpleValueType)(SVT.getSimpleVT().SimpleTy - 1);
318       if (ConstantFPSDNode::isValueValidForType(SVT, APF) &&
319           // Only do this if the target has a native EXTLOAD instruction from
320           // smaller type.
321           TLI.isLoadExtLegal(ISD::EXTLOAD, OrigVT, SVT) &&
322           TLI.ShouldShrinkFPConstant(OrigVT)) {
323         Type *SType = SVT.getTypeForEVT(*DAG.getContext());
324         LLVMC = cast<ConstantFP>(ConstantExpr::getFPTrunc(LLVMC, SType));
325         VT = SVT;
326         Extend = true;
327       }
328     }
329   }
330 
331   SDValue CPIdx =
332       DAG.getConstantPool(LLVMC, TLI.getPointerTy(DAG.getDataLayout()));
333   Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
334   if (Extend) {
335     SDValue Result = DAG.getExtLoad(
336         ISD::EXTLOAD, dl, OrigVT, DAG.getEntryNode(), CPIdx,
337         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), VT,
338         Alignment);
339     return Result;
340   }
341   SDValue Result = DAG.getLoad(
342       OrigVT, dl, DAG.getEntryNode(), CPIdx,
343       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
344   return Result;
345 }
346 
347 /// Expands the Constant node to a load from the constant pool.
348 SDValue SelectionDAGLegalize::ExpandConstant(ConstantSDNode *CP) {
349   SDLoc dl(CP);
350   EVT VT = CP->getValueType(0);
351   SDValue CPIdx = DAG.getConstantPool(CP->getConstantIntValue(),
352                                       TLI.getPointerTy(DAG.getDataLayout()));
353   Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
354   SDValue Result = DAG.getLoad(
355       VT, dl, DAG.getEntryNode(), CPIdx,
356       MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), Alignment);
357   return Result;
358 }
359 
360 /// Some target cannot handle a variable insertion index for the
361 /// INSERT_VECTOR_ELT instruction.  In this case, it
362 /// is necessary to spill the vector being inserted into to memory, perform
363 /// the insert there, and then read the result back.
364 SDValue SelectionDAGLegalize::PerformInsertVectorEltInMemory(SDValue Vec,
365                                                              SDValue Val,
366                                                              SDValue Idx,
367                                                              const SDLoc &dl) {
368   SDValue Tmp1 = Vec;
369   SDValue Tmp2 = Val;
370   SDValue Tmp3 = Idx;
371 
372   // If the target doesn't support this, we have to spill the input vector
373   // to a temporary stack slot, update the element, then reload it.  This is
374   // badness.  We could also load the value into a vector register (either
375   // with a "move to register" or "extload into register" instruction, then
376   // permute it into place, if the idx is a constant and if the idx is
377   // supported by the target.
378   EVT VT    = Tmp1.getValueType();
379   EVT EltVT = VT.getVectorElementType();
380   SDValue StackPtr = DAG.CreateStackTemporary(VT);
381 
382   int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
383 
384   // Store the vector.
385   SDValue Ch = DAG.getStore(
386       DAG.getEntryNode(), dl, Tmp1, StackPtr,
387       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
388 
389   SDValue StackPtr2 = TLI.getVectorElementPointer(DAG, StackPtr, VT, Tmp3);
390 
391   // Store the scalar value.
392   Ch = DAG.getTruncStore(
393       Ch, dl, Tmp2, StackPtr2,
394       MachinePointerInfo::getUnknownStack(DAG.getMachineFunction()), EltVT);
395   // Load the updated vector.
396   return DAG.getLoad(VT, dl, Ch, StackPtr, MachinePointerInfo::getFixedStack(
397                                                DAG.getMachineFunction(), SPFI));
398 }
399 
400 SDValue SelectionDAGLegalize::ExpandINSERT_VECTOR_ELT(SDValue Vec, SDValue Val,
401                                                       SDValue Idx,
402                                                       const SDLoc &dl) {
403   if (ConstantSDNode *InsertPos = dyn_cast<ConstantSDNode>(Idx)) {
404     // SCALAR_TO_VECTOR requires that the type of the value being inserted
405     // match the element type of the vector being created, except for
406     // integers in which case the inserted value can be over width.
407     EVT EltVT = Vec.getValueType().getVectorElementType();
408     if (Val.getValueType() == EltVT ||
409         (EltVT.isInteger() && Val.getValueType().bitsGE(EltVT))) {
410       SDValue ScVec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl,
411                                   Vec.getValueType(), Val);
412 
413       unsigned NumElts = Vec.getValueType().getVectorNumElements();
414       // We generate a shuffle of InVec and ScVec, so the shuffle mask
415       // should be 0,1,2,3,4,5... with the appropriate element replaced with
416       // elt 0 of the RHS.
417       SmallVector<int, 8> ShufOps;
418       for (unsigned i = 0; i != NumElts; ++i)
419         ShufOps.push_back(i != InsertPos->getZExtValue() ? i : NumElts);
420 
421       return DAG.getVectorShuffle(Vec.getValueType(), dl, Vec, ScVec, ShufOps);
422     }
423   }
424   return PerformInsertVectorEltInMemory(Vec, Val, Idx, dl);
425 }
426 
427 SDValue SelectionDAGLegalize::OptimizeFloatStore(StoreSDNode* ST) {
428   if (!ISD::isNormalStore(ST))
429     return SDValue();
430 
431   LLVM_DEBUG(dbgs() << "Optimizing float store operations\n");
432   // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
433   // FIXME: We shouldn't do this for TargetConstantFP's.
434   // FIXME: move this to the DAG Combiner!  Note that we can't regress due
435   // to phase ordering between legalized code and the dag combiner.  This
436   // probably means that we need to integrate dag combiner and legalizer
437   // together.
438   // We generally can't do this one for long doubles.
439   SDValue Chain = ST->getChain();
440   SDValue Ptr = ST->getBasePtr();
441   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
442   AAMDNodes AAInfo = ST->getAAInfo();
443   SDLoc dl(ST);
444   if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(ST->getValue())) {
445     if (CFP->getValueType(0) == MVT::f32 &&
446         TLI.isTypeLegal(MVT::i32)) {
447       SDValue Con = DAG.getConstant(CFP->getValueAPF().
448                                       bitcastToAPInt().zextOrTrunc(32),
449                                     SDLoc(CFP), MVT::i32);
450       return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
451                           ST->getOriginalAlign(), MMOFlags, AAInfo);
452     }
453 
454     if (CFP->getValueType(0) == MVT::f64) {
455       // If this target supports 64-bit registers, do a single 64-bit store.
456       if (TLI.isTypeLegal(MVT::i64)) {
457         SDValue Con = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
458                                       zextOrTrunc(64), SDLoc(CFP), MVT::i64);
459         return DAG.getStore(Chain, dl, Con, Ptr, ST->getPointerInfo(),
460                             ST->getOriginalAlign(), MMOFlags, AAInfo);
461       }
462 
463       if (TLI.isTypeLegal(MVT::i32) && !ST->isVolatile()) {
464         // Otherwise, if the target supports 32-bit registers, use 2 32-bit
465         // stores.  If the target supports neither 32- nor 64-bits, this
466         // xform is certainly not worth it.
467         const APInt &IntVal = CFP->getValueAPF().bitcastToAPInt();
468         SDValue Lo = DAG.getConstant(IntVal.trunc(32), dl, MVT::i32);
469         SDValue Hi = DAG.getConstant(IntVal.lshr(32).trunc(32), dl, MVT::i32);
470         if (DAG.getDataLayout().isBigEndian())
471           std::swap(Lo, Hi);
472 
473         Lo = DAG.getStore(Chain, dl, Lo, Ptr, ST->getPointerInfo(),
474                           ST->getOriginalAlign(), MMOFlags, AAInfo);
475         Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(4), dl);
476         Hi = DAG.getStore(Chain, dl, Hi, Ptr,
477                           ST->getPointerInfo().getWithOffset(4),
478                           ST->getOriginalAlign(), MMOFlags, AAInfo);
479 
480         return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
481       }
482     }
483   }
484   return SDValue(nullptr, 0);
485 }
486 
487 void SelectionDAGLegalize::LegalizeStoreOps(SDNode *Node) {
488   StoreSDNode *ST = cast<StoreSDNode>(Node);
489   SDValue Chain = ST->getChain();
490   SDValue Ptr = ST->getBasePtr();
491   SDLoc dl(Node);
492 
493   MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
494   AAMDNodes AAInfo = ST->getAAInfo();
495 
496   if (!ST->isTruncatingStore()) {
497     LLVM_DEBUG(dbgs() << "Legalizing store operation\n");
498     if (SDNode *OptStore = OptimizeFloatStore(ST).getNode()) {
499       ReplaceNode(ST, OptStore);
500       return;
501     }
502 
503     SDValue Value = ST->getValue();
504     MVT VT = Value.getSimpleValueType();
505     switch (TLI.getOperationAction(ISD::STORE, VT)) {
506     default: llvm_unreachable("This action is not supported yet!");
507     case TargetLowering::Legal: {
508       // If this is an unaligned store and the target doesn't support it,
509       // expand it.
510       EVT MemVT = ST->getMemoryVT();
511       const DataLayout &DL = DAG.getDataLayout();
512       if (!TLI.allowsMemoryAccessForAlignment(*DAG.getContext(), DL, MemVT,
513                                               *ST->getMemOperand())) {
514         LLVM_DEBUG(dbgs() << "Expanding unsupported unaligned store\n");
515         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
516         ReplaceNode(SDValue(ST, 0), Result);
517       } else
518         LLVM_DEBUG(dbgs() << "Legal store\n");
519       break;
520     }
521     case TargetLowering::Custom: {
522       LLVM_DEBUG(dbgs() << "Trying custom lowering\n");
523       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
524       if (Res && Res != SDValue(Node, 0))
525         ReplaceNode(SDValue(Node, 0), Res);
526       return;
527     }
528     case TargetLowering::Promote: {
529       MVT NVT = TLI.getTypeToPromoteTo(ISD::STORE, VT);
530       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
531              "Can only promote stores to same size type");
532       Value = DAG.getNode(ISD::BITCAST, dl, NVT, Value);
533       SDValue Result = DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
534                                     ST->getOriginalAlign(), MMOFlags, AAInfo);
535       ReplaceNode(SDValue(Node, 0), Result);
536       break;
537     }
538     }
539     return;
540   }
541 
542   LLVM_DEBUG(dbgs() << "Legalizing truncating store operations\n");
543   SDValue Value = ST->getValue();
544   EVT StVT = ST->getMemoryVT();
545   TypeSize StWidth = StVT.getSizeInBits();
546   TypeSize StSize = StVT.getStoreSizeInBits();
547   auto &DL = DAG.getDataLayout();
548 
549   if (StWidth != StSize) {
550     // Promote to a byte-sized store with upper bits zero if not
551     // storing an integral number of bytes.  For example, promote
552     // TRUNCSTORE:i1 X -> TRUNCSTORE:i8 (and X, 1)
553     EVT NVT = EVT::getIntegerVT(*DAG.getContext(), StSize.getFixedSize());
554     Value = DAG.getZeroExtendInReg(Value, dl, StVT);
555     SDValue Result =
556         DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(), NVT,
557                           ST->getOriginalAlign(), MMOFlags, AAInfo);
558     ReplaceNode(SDValue(Node, 0), Result);
559   } else if (!StVT.isVector() && !isPowerOf2_64(StWidth.getFixedSize())) {
560     // If not storing a power-of-2 number of bits, expand as two stores.
561     assert(!StVT.isVector() && "Unsupported truncstore!");
562     unsigned StWidthBits = StWidth.getFixedSize();
563     unsigned LogStWidth = Log2_32(StWidthBits);
564     assert(LogStWidth < 32);
565     unsigned RoundWidth = 1 << LogStWidth;
566     assert(RoundWidth < StWidthBits);
567     unsigned ExtraWidth = StWidthBits - RoundWidth;
568     assert(ExtraWidth < RoundWidth);
569     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
570            "Store size not an integral number of bytes!");
571     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
572     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
573     SDValue Lo, Hi;
574     unsigned IncrementSize;
575 
576     if (DL.isLittleEndian()) {
577       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 X, TRUNCSTORE@+2:i8 (srl X, 16)
578       // Store the bottom RoundWidth bits.
579       Lo = DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
580                              RoundVT, ST->getOriginalAlign(), MMOFlags, AAInfo);
581 
582       // Store the remaining ExtraWidth bits.
583       IncrementSize = RoundWidth / 8;
584       Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(IncrementSize), dl);
585       Hi = DAG.getNode(
586           ISD::SRL, dl, Value.getValueType(), Value,
587           DAG.getConstant(RoundWidth, dl,
588                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
589       Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr,
590                              ST->getPointerInfo().getWithOffset(IncrementSize),
591                              ExtraVT, ST->getOriginalAlign(), MMOFlags, AAInfo);
592     } else {
593       // Big endian - avoid unaligned stores.
594       // TRUNCSTORE:i24 X -> TRUNCSTORE:i16 (srl X, 8), TRUNCSTORE@+2:i8 X
595       // Store the top RoundWidth bits.
596       Hi = DAG.getNode(
597           ISD::SRL, dl, Value.getValueType(), Value,
598           DAG.getConstant(ExtraWidth, dl,
599                           TLI.getShiftAmountTy(Value.getValueType(), DL)));
600       Hi = DAG.getTruncStore(Chain, dl, Hi, Ptr, ST->getPointerInfo(), RoundVT,
601                              ST->getOriginalAlign(), MMOFlags, AAInfo);
602 
603       // Store the remaining ExtraWidth bits.
604       IncrementSize = RoundWidth / 8;
605       Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
606                         DAG.getConstant(IncrementSize, dl,
607                                         Ptr.getValueType()));
608       Lo = DAG.getTruncStore(Chain, dl, Value, Ptr,
609                              ST->getPointerInfo().getWithOffset(IncrementSize),
610                              ExtraVT, ST->getOriginalAlign(), MMOFlags, AAInfo);
611     }
612 
613     // The order of the stores doesn't matter.
614     SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
615     ReplaceNode(SDValue(Node, 0), Result);
616   } else {
617     switch (TLI.getTruncStoreAction(ST->getValue().getValueType(), StVT)) {
618     default: llvm_unreachable("This action is not supported yet!");
619     case TargetLowering::Legal: {
620       EVT MemVT = ST->getMemoryVT();
621       // If this is an unaligned store and the target doesn't support it,
622       // expand it.
623       if (!TLI.allowsMemoryAccessForAlignment(*DAG.getContext(), DL, MemVT,
624                                               *ST->getMemOperand())) {
625         SDValue Result = TLI.expandUnalignedStore(ST, DAG);
626         ReplaceNode(SDValue(ST, 0), Result);
627       }
628       break;
629     }
630     case TargetLowering::Custom: {
631       SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
632       if (Res && Res != SDValue(Node, 0))
633         ReplaceNode(SDValue(Node, 0), Res);
634       return;
635     }
636     case TargetLowering::Expand:
637       assert(!StVT.isVector() &&
638              "Vector Stores are handled in LegalizeVectorOps");
639 
640       SDValue Result;
641 
642       // TRUNCSTORE:i16 i32 -> STORE i16
643       if (TLI.isTypeLegal(StVT)) {
644         Value = DAG.getNode(ISD::TRUNCATE, dl, StVT, Value);
645         Result = DAG.getStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
646                               ST->getOriginalAlign(), MMOFlags, AAInfo);
647       } else {
648         // The in-memory type isn't legal. Truncate to the type it would promote
649         // to, and then do a truncstore.
650         Value = DAG.getNode(ISD::TRUNCATE, dl,
651                             TLI.getTypeToTransformTo(*DAG.getContext(), StVT),
652                             Value);
653         Result =
654             DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(), StVT,
655                               ST->getOriginalAlign(), MMOFlags, AAInfo);
656       }
657 
658       ReplaceNode(SDValue(Node, 0), Result);
659       break;
660     }
661   }
662 }
663 
664 void SelectionDAGLegalize::LegalizeLoadOps(SDNode *Node) {
665   LoadSDNode *LD = cast<LoadSDNode>(Node);
666   SDValue Chain = LD->getChain();  // The chain.
667   SDValue Ptr = LD->getBasePtr();  // The base pointer.
668   SDValue Value;                   // The value returned by the load op.
669   SDLoc dl(Node);
670 
671   ISD::LoadExtType ExtType = LD->getExtensionType();
672   if (ExtType == ISD::NON_EXTLOAD) {
673     LLVM_DEBUG(dbgs() << "Legalizing non-extending load operation\n");
674     MVT VT = Node->getSimpleValueType(0);
675     SDValue RVal = SDValue(Node, 0);
676     SDValue RChain = SDValue(Node, 1);
677 
678     switch (TLI.getOperationAction(Node->getOpcode(), VT)) {
679     default: llvm_unreachable("This action is not supported yet!");
680     case TargetLowering::Legal: {
681       EVT MemVT = LD->getMemoryVT();
682       const DataLayout &DL = DAG.getDataLayout();
683       // If this is an unaligned load and the target doesn't support it,
684       // expand it.
685       if (!TLI.allowsMemoryAccessForAlignment(*DAG.getContext(), DL, MemVT,
686                                               *LD->getMemOperand())) {
687         std::tie(RVal, RChain) = TLI.expandUnalignedLoad(LD, DAG);
688       }
689       break;
690     }
691     case TargetLowering::Custom:
692       if (SDValue Res = TLI.LowerOperation(RVal, DAG)) {
693         RVal = Res;
694         RChain = Res.getValue(1);
695       }
696       break;
697 
698     case TargetLowering::Promote: {
699       MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
700       assert(NVT.getSizeInBits() == VT.getSizeInBits() &&
701              "Can only promote loads to same size type");
702 
703       SDValue Res = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getMemOperand());
704       RVal = DAG.getNode(ISD::BITCAST, dl, VT, Res);
705       RChain = Res.getValue(1);
706       break;
707     }
708     }
709     if (RChain.getNode() != Node) {
710       assert(RVal.getNode() != Node && "Load must be completely replaced");
711       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), RVal);
712       DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), RChain);
713       if (UpdatedNodes) {
714         UpdatedNodes->insert(RVal.getNode());
715         UpdatedNodes->insert(RChain.getNode());
716       }
717       ReplacedNode(Node);
718     }
719     return;
720   }
721 
722   LLVM_DEBUG(dbgs() << "Legalizing extending load operation\n");
723   EVT SrcVT = LD->getMemoryVT();
724   TypeSize SrcWidth = SrcVT.getSizeInBits();
725   MachineMemOperand::Flags MMOFlags = LD->getMemOperand()->getFlags();
726   AAMDNodes AAInfo = LD->getAAInfo();
727 
728   if (SrcWidth != SrcVT.getStoreSizeInBits() &&
729       // Some targets pretend to have an i1 loading operation, and actually
730       // load an i8.  This trick is correct for ZEXTLOAD because the top 7
731       // bits are guaranteed to be zero; it helps the optimizers understand
732       // that these bits are zero.  It is also useful for EXTLOAD, since it
733       // tells the optimizers that those bits are undefined.  It would be
734       // nice to have an effective generic way of getting these benefits...
735       // Until such a way is found, don't insist on promoting i1 here.
736       (SrcVT != MVT::i1 ||
737        TLI.getLoadExtAction(ExtType, Node->getValueType(0), MVT::i1) ==
738          TargetLowering::Promote)) {
739     // Promote to a byte-sized load if not loading an integral number of
740     // bytes.  For example, promote EXTLOAD:i20 -> EXTLOAD:i24.
741     unsigned NewWidth = SrcVT.getStoreSizeInBits();
742     EVT NVT = EVT::getIntegerVT(*DAG.getContext(), NewWidth);
743     SDValue Ch;
744 
745     // The extra bits are guaranteed to be zero, since we stored them that
746     // way.  A zext load from NVT thus automatically gives zext from SrcVT.
747 
748     ISD::LoadExtType NewExtType =
749       ExtType == ISD::ZEXTLOAD ? ISD::ZEXTLOAD : ISD::EXTLOAD;
750 
751     SDValue Result = DAG.getExtLoad(NewExtType, dl, Node->getValueType(0),
752                                     Chain, Ptr, LD->getPointerInfo(), NVT,
753                                     LD->getOriginalAlign(), MMOFlags, AAInfo);
754 
755     Ch = Result.getValue(1); // The chain.
756 
757     if (ExtType == ISD::SEXTLOAD)
758       // Having the top bits zero doesn't help when sign extending.
759       Result = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
760                            Result.getValueType(),
761                            Result, DAG.getValueType(SrcVT));
762     else if (ExtType == ISD::ZEXTLOAD || NVT == Result.getValueType())
763       // All the top bits are guaranteed to be zero - inform the optimizers.
764       Result = DAG.getNode(ISD::AssertZext, dl,
765                            Result.getValueType(), Result,
766                            DAG.getValueType(SrcVT));
767 
768     Value = Result;
769     Chain = Ch;
770   } else if (!isPowerOf2_64(SrcWidth.getKnownMinSize())) {
771     // If not loading a power-of-2 number of bits, expand as two loads.
772     assert(!SrcVT.isVector() && "Unsupported extload!");
773     unsigned SrcWidthBits = SrcWidth.getFixedSize();
774     unsigned LogSrcWidth = Log2_32(SrcWidthBits);
775     assert(LogSrcWidth < 32);
776     unsigned RoundWidth = 1 << LogSrcWidth;
777     assert(RoundWidth < SrcWidthBits);
778     unsigned ExtraWidth = SrcWidthBits - RoundWidth;
779     assert(ExtraWidth < RoundWidth);
780     assert(!(RoundWidth % 8) && !(ExtraWidth % 8) &&
781            "Load size not an integral number of bytes!");
782     EVT RoundVT = EVT::getIntegerVT(*DAG.getContext(), RoundWidth);
783     EVT ExtraVT = EVT::getIntegerVT(*DAG.getContext(), ExtraWidth);
784     SDValue Lo, Hi, Ch;
785     unsigned IncrementSize;
786     auto &DL = DAG.getDataLayout();
787 
788     if (DL.isLittleEndian()) {
789       // EXTLOAD:i24 -> ZEXTLOAD:i16 | (shl EXTLOAD@+2:i8, 16)
790       // Load the bottom RoundWidth bits.
791       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
792                           LD->getPointerInfo(), RoundVT, LD->getOriginalAlign(),
793                           MMOFlags, AAInfo);
794 
795       // Load the remaining ExtraWidth bits.
796       IncrementSize = RoundWidth / 8;
797       Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(IncrementSize), dl);
798       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
799                           LD->getPointerInfo().getWithOffset(IncrementSize),
800                           ExtraVT, LD->getOriginalAlign(), MMOFlags, AAInfo);
801 
802       // Build a factor node to remember that this load is independent of
803       // the other one.
804       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
805                        Hi.getValue(1));
806 
807       // Move the top bits to the right place.
808       Hi = DAG.getNode(
809           ISD::SHL, dl, Hi.getValueType(), Hi,
810           DAG.getConstant(RoundWidth, dl,
811                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
812 
813       // Join the hi and lo parts.
814       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
815     } else {
816       // Big endian - avoid unaligned loads.
817       // EXTLOAD:i24 -> (shl EXTLOAD:i16, 8) | ZEXTLOAD@+2:i8
818       // Load the top RoundWidth bits.
819       Hi = DAG.getExtLoad(ExtType, dl, Node->getValueType(0), Chain, Ptr,
820                           LD->getPointerInfo(), RoundVT, LD->getOriginalAlign(),
821                           MMOFlags, AAInfo);
822 
823       // Load the remaining ExtraWidth bits.
824       IncrementSize = RoundWidth / 8;
825       Ptr = DAG.getMemBasePlusOffset(Ptr, TypeSize::Fixed(IncrementSize), dl);
826       Lo = DAG.getExtLoad(ISD::ZEXTLOAD, dl, Node->getValueType(0), Chain, Ptr,
827                           LD->getPointerInfo().getWithOffset(IncrementSize),
828                           ExtraVT, LD->getOriginalAlign(), MMOFlags, AAInfo);
829 
830       // Build a factor node to remember that this load is independent of
831       // the other one.
832       Ch = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
833                        Hi.getValue(1));
834 
835       // Move the top bits to the right place.
836       Hi = DAG.getNode(
837           ISD::SHL, dl, Hi.getValueType(), Hi,
838           DAG.getConstant(ExtraWidth, dl,
839                           TLI.getShiftAmountTy(Hi.getValueType(), DL)));
840 
841       // Join the hi and lo parts.
842       Value = DAG.getNode(ISD::OR, dl, Node->getValueType(0), Lo, Hi);
843     }
844 
845     Chain = Ch;
846   } else {
847     bool isCustom = false;
848     switch (TLI.getLoadExtAction(ExtType, Node->getValueType(0),
849                                  SrcVT.getSimpleVT())) {
850     default: llvm_unreachable("This action is not supported yet!");
851     case TargetLowering::Custom:
852       isCustom = true;
853       LLVM_FALLTHROUGH;
854     case TargetLowering::Legal:
855       Value = SDValue(Node, 0);
856       Chain = SDValue(Node, 1);
857 
858       if (isCustom) {
859         if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
860           Value = Res;
861           Chain = Res.getValue(1);
862         }
863       } else {
864         // If this is an unaligned load and the target doesn't support it,
865         // expand it.
866         EVT MemVT = LD->getMemoryVT();
867         const DataLayout &DL = DAG.getDataLayout();
868         if (!TLI.allowsMemoryAccess(*DAG.getContext(), DL, MemVT,
869                                     *LD->getMemOperand())) {
870           std::tie(Value, Chain) = TLI.expandUnalignedLoad(LD, DAG);
871         }
872       }
873       break;
874 
875     case TargetLowering::Expand: {
876       EVT DestVT = Node->getValueType(0);
877       if (!TLI.isLoadExtLegal(ISD::EXTLOAD, DestVT, SrcVT)) {
878         // If the source type is not legal, see if there is a legal extload to
879         // an intermediate type that we can then extend further.
880         EVT LoadVT = TLI.getRegisterType(SrcVT.getSimpleVT());
881         if (TLI.isTypeLegal(SrcVT) || // Same as SrcVT == LoadVT?
882             TLI.isLoadExtLegal(ExtType, LoadVT, SrcVT)) {
883           // If we are loading a legal type, this is a non-extload followed by a
884           // full extend.
885           ISD::LoadExtType MidExtType =
886               (LoadVT == SrcVT) ? ISD::NON_EXTLOAD : ExtType;
887 
888           SDValue Load = DAG.getExtLoad(MidExtType, dl, LoadVT, Chain, Ptr,
889                                         SrcVT, LD->getMemOperand());
890           unsigned ExtendOp =
891               ISD::getExtForLoadExtType(SrcVT.isFloatingPoint(), ExtType);
892           Value = DAG.getNode(ExtendOp, dl, Node->getValueType(0), Load);
893           Chain = Load.getValue(1);
894           break;
895         }
896 
897         // Handle the special case of fp16 extloads. EXTLOAD doesn't have the
898         // normal undefined upper bits behavior to allow using an in-reg extend
899         // with the illegal FP type, so load as an integer and do the
900         // from-integer conversion.
901         if (SrcVT.getScalarType() == MVT::f16) {
902           EVT ISrcVT = SrcVT.changeTypeToInteger();
903           EVT IDestVT = DestVT.changeTypeToInteger();
904           EVT ILoadVT = TLI.getRegisterType(IDestVT.getSimpleVT());
905 
906           SDValue Result = DAG.getExtLoad(ISD::ZEXTLOAD, dl, ILoadVT, Chain,
907                                           Ptr, ISrcVT, LD->getMemOperand());
908           Value = DAG.getNode(ISD::FP16_TO_FP, dl, DestVT, Result);
909           Chain = Result.getValue(1);
910           break;
911         }
912       }
913 
914       assert(!SrcVT.isVector() &&
915              "Vector Loads are handled in LegalizeVectorOps");
916 
917       // FIXME: This does not work for vectors on most targets.  Sign-
918       // and zero-extend operations are currently folded into extending
919       // loads, whether they are legal or not, and then we end up here
920       // without any support for legalizing them.
921       assert(ExtType != ISD::EXTLOAD &&
922              "EXTLOAD should always be supported!");
923       // Turn the unsupported load into an EXTLOAD followed by an
924       // explicit zero/sign extend inreg.
925       SDValue Result = DAG.getExtLoad(ISD::EXTLOAD, dl,
926                                       Node->getValueType(0),
927                                       Chain, Ptr, SrcVT,
928                                       LD->getMemOperand());
929       SDValue ValRes;
930       if (ExtType == ISD::SEXTLOAD)
931         ValRes = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl,
932                              Result.getValueType(),
933                              Result, DAG.getValueType(SrcVT));
934       else
935         ValRes = DAG.getZeroExtendInReg(Result, dl, SrcVT);
936       Value = ValRes;
937       Chain = Result.getValue(1);
938       break;
939     }
940     }
941   }
942 
943   // Since loads produce two values, make sure to remember that we legalized
944   // both of them.
945   if (Chain.getNode() != Node) {
946     assert(Value.getNode() != Node && "Load must be completely replaced");
947     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Value);
948     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
949     if (UpdatedNodes) {
950       UpdatedNodes->insert(Value.getNode());
951       UpdatedNodes->insert(Chain.getNode());
952     }
953     ReplacedNode(Node);
954   }
955 }
956 
957 /// Return a legal replacement for the given operation, with all legal operands.
958 void SelectionDAGLegalize::LegalizeOp(SDNode *Node) {
959   LLVM_DEBUG(dbgs() << "\nLegalizing: "; Node->dump(&DAG));
960 
961   // Allow illegal target nodes and illegal registers.
962   if (Node->getOpcode() == ISD::TargetConstant ||
963       Node->getOpcode() == ISD::Register)
964     return;
965 
966 #ifndef NDEBUG
967   for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
968     assert(TLI.getTypeAction(*DAG.getContext(), Node->getValueType(i)) ==
969              TargetLowering::TypeLegal &&
970            "Unexpected illegal type!");
971 
972   for (const SDValue &Op : Node->op_values())
973     assert((TLI.getTypeAction(*DAG.getContext(), Op.getValueType()) ==
974               TargetLowering::TypeLegal ||
975             Op.getOpcode() == ISD::TargetConstant ||
976             Op.getOpcode() == ISD::Register) &&
977             "Unexpected illegal type!");
978 #endif
979 
980   // Figure out the correct action; the way to query this varies by opcode
981   TargetLowering::LegalizeAction Action = TargetLowering::Legal;
982   bool SimpleFinishLegalizing = true;
983   switch (Node->getOpcode()) {
984   case ISD::INTRINSIC_W_CHAIN:
985   case ISD::INTRINSIC_WO_CHAIN:
986   case ISD::INTRINSIC_VOID:
987   case ISD::STACKSAVE:
988     Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
989     break;
990   case ISD::GET_DYNAMIC_AREA_OFFSET:
991     Action = TLI.getOperationAction(Node->getOpcode(),
992                                     Node->getValueType(0));
993     break;
994   case ISD::VAARG:
995     Action = TLI.getOperationAction(Node->getOpcode(),
996                                     Node->getValueType(0));
997     if (Action != TargetLowering::Promote)
998       Action = TLI.getOperationAction(Node->getOpcode(), MVT::Other);
999     break;
1000   case ISD::FP_TO_FP16:
1001   case ISD::SINT_TO_FP:
1002   case ISD::UINT_TO_FP:
1003   case ISD::EXTRACT_VECTOR_ELT:
1004   case ISD::LROUND:
1005   case ISD::LLROUND:
1006   case ISD::LRINT:
1007   case ISD::LLRINT:
1008     Action = TLI.getOperationAction(Node->getOpcode(),
1009                                     Node->getOperand(0).getValueType());
1010     break;
1011   case ISD::STRICT_FP_TO_FP16:
1012   case ISD::STRICT_SINT_TO_FP:
1013   case ISD::STRICT_UINT_TO_FP:
1014   case ISD::STRICT_LRINT:
1015   case ISD::STRICT_LLRINT:
1016   case ISD::STRICT_LROUND:
1017   case ISD::STRICT_LLROUND:
1018     // These pseudo-ops are the same as the other STRICT_ ops except
1019     // they are registered with setOperationAction() using the input type
1020     // instead of the output type.
1021     Action = TLI.getOperationAction(Node->getOpcode(),
1022                                     Node->getOperand(1).getValueType());
1023     break;
1024   case ISD::SIGN_EXTEND_INREG: {
1025     EVT InnerType = cast<VTSDNode>(Node->getOperand(1))->getVT();
1026     Action = TLI.getOperationAction(Node->getOpcode(), InnerType);
1027     break;
1028   }
1029   case ISD::ATOMIC_STORE:
1030     Action = TLI.getOperationAction(Node->getOpcode(),
1031                                     Node->getOperand(2).getValueType());
1032     break;
1033   case ISD::SELECT_CC:
1034   case ISD::STRICT_FSETCC:
1035   case ISD::STRICT_FSETCCS:
1036   case ISD::SETCC:
1037   case ISD::BR_CC: {
1038     unsigned CCOperand = Node->getOpcode() == ISD::SELECT_CC ? 4 :
1039                          Node->getOpcode() == ISD::STRICT_FSETCC ? 3 :
1040                          Node->getOpcode() == ISD::STRICT_FSETCCS ? 3 :
1041                          Node->getOpcode() == ISD::SETCC ? 2 : 1;
1042     unsigned CompareOperand = Node->getOpcode() == ISD::BR_CC ? 2 :
1043                               Node->getOpcode() == ISD::STRICT_FSETCC ? 1 :
1044                               Node->getOpcode() == ISD::STRICT_FSETCCS ? 1 : 0;
1045     MVT OpVT = Node->getOperand(CompareOperand).getSimpleValueType();
1046     ISD::CondCode CCCode =
1047         cast<CondCodeSDNode>(Node->getOperand(CCOperand))->get();
1048     Action = TLI.getCondCodeAction(CCCode, OpVT);
1049     if (Action == TargetLowering::Legal) {
1050       if (Node->getOpcode() == ISD::SELECT_CC)
1051         Action = TLI.getOperationAction(Node->getOpcode(),
1052                                         Node->getValueType(0));
1053       else
1054         Action = TLI.getOperationAction(Node->getOpcode(), OpVT);
1055     }
1056     break;
1057   }
1058   case ISD::LOAD:
1059   case ISD::STORE:
1060     // FIXME: Model these properly.  LOAD and STORE are complicated, and
1061     // STORE expects the unlegalized operand in some cases.
1062     SimpleFinishLegalizing = false;
1063     break;
1064   case ISD::CALLSEQ_START:
1065   case ISD::CALLSEQ_END:
1066     // FIXME: This shouldn't be necessary.  These nodes have special properties
1067     // dealing with the recursive nature of legalization.  Removing this
1068     // special case should be done as part of making LegalizeDAG non-recursive.
1069     SimpleFinishLegalizing = false;
1070     break;
1071   case ISD::EXTRACT_ELEMENT:
1072   case ISD::FLT_ROUNDS_:
1073   case ISD::MERGE_VALUES:
1074   case ISD::EH_RETURN:
1075   case ISD::FRAME_TO_ARGS_OFFSET:
1076   case ISD::EH_DWARF_CFA:
1077   case ISD::EH_SJLJ_SETJMP:
1078   case ISD::EH_SJLJ_LONGJMP:
1079   case ISD::EH_SJLJ_SETUP_DISPATCH:
1080     // These operations lie about being legal: when they claim to be legal,
1081     // they should actually be expanded.
1082     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1083     if (Action == TargetLowering::Legal)
1084       Action = TargetLowering::Expand;
1085     break;
1086   case ISD::INIT_TRAMPOLINE:
1087   case ISD::ADJUST_TRAMPOLINE:
1088   case ISD::FRAMEADDR:
1089   case ISD::RETURNADDR:
1090   case ISD::ADDROFRETURNADDR:
1091   case ISD::SPONENTRY:
1092     // These operations lie about being legal: when they claim to be legal,
1093     // they should actually be custom-lowered.
1094     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1095     if (Action == TargetLowering::Legal)
1096       Action = TargetLowering::Custom;
1097     break;
1098   case ISD::READCYCLECOUNTER:
1099     // READCYCLECOUNTER returns an i64, even if type legalization might have
1100     // expanded that to several smaller types.
1101     Action = TLI.getOperationAction(Node->getOpcode(), MVT::i64);
1102     break;
1103   case ISD::READ_REGISTER:
1104   case ISD::WRITE_REGISTER:
1105     // Named register is legal in the DAG, but blocked by register name
1106     // selection if not implemented by target (to chose the correct register)
1107     // They'll be converted to Copy(To/From)Reg.
1108     Action = TargetLowering::Legal;
1109     break;
1110   case ISD::DEBUGTRAP:
1111     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1112     if (Action == TargetLowering::Expand) {
1113       // replace ISD::DEBUGTRAP with ISD::TRAP
1114       SDValue NewVal;
1115       NewVal = DAG.getNode(ISD::TRAP, SDLoc(Node), Node->getVTList(),
1116                            Node->getOperand(0));
1117       ReplaceNode(Node, NewVal.getNode());
1118       LegalizeOp(NewVal.getNode());
1119       return;
1120     }
1121     break;
1122   case ISD::SADDSAT:
1123   case ISD::UADDSAT:
1124   case ISD::SSUBSAT:
1125   case ISD::USUBSAT:
1126   case ISD::SSHLSAT:
1127   case ISD::USHLSAT: {
1128     Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1129     break;
1130   }
1131   case ISD::SMULFIX:
1132   case ISD::SMULFIXSAT:
1133   case ISD::UMULFIX:
1134   case ISD::UMULFIXSAT:
1135   case ISD::SDIVFIX:
1136   case ISD::SDIVFIXSAT:
1137   case ISD::UDIVFIX:
1138   case ISD::UDIVFIXSAT: {
1139     unsigned Scale = Node->getConstantOperandVal(2);
1140     Action = TLI.getFixedPointOperationAction(Node->getOpcode(),
1141                                               Node->getValueType(0), Scale);
1142     break;
1143   }
1144   case ISD::MSCATTER:
1145     Action = TLI.getOperationAction(Node->getOpcode(),
1146                     cast<MaskedScatterSDNode>(Node)->getValue().getValueType());
1147     break;
1148   case ISD::MSTORE:
1149     Action = TLI.getOperationAction(Node->getOpcode(),
1150                     cast<MaskedStoreSDNode>(Node)->getValue().getValueType());
1151     break;
1152   case ISD::VECREDUCE_FADD:
1153   case ISD::VECREDUCE_FMUL:
1154   case ISD::VECREDUCE_ADD:
1155   case ISD::VECREDUCE_MUL:
1156   case ISD::VECREDUCE_AND:
1157   case ISD::VECREDUCE_OR:
1158   case ISD::VECREDUCE_XOR:
1159   case ISD::VECREDUCE_SMAX:
1160   case ISD::VECREDUCE_SMIN:
1161   case ISD::VECREDUCE_UMAX:
1162   case ISD::VECREDUCE_UMIN:
1163   case ISD::VECREDUCE_FMAX:
1164   case ISD::VECREDUCE_FMIN:
1165     Action = TLI.getOperationAction(
1166         Node->getOpcode(), Node->getOperand(0).getValueType());
1167     break;
1168   default:
1169     if (Node->getOpcode() >= ISD::BUILTIN_OP_END) {
1170       Action = TargetLowering::Legal;
1171     } else {
1172       Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
1173     }
1174     break;
1175   }
1176 
1177   if (SimpleFinishLegalizing) {
1178     SDNode *NewNode = Node;
1179     switch (Node->getOpcode()) {
1180     default: break;
1181     case ISD::SHL:
1182     case ISD::SRL:
1183     case ISD::SRA:
1184     case ISD::ROTL:
1185     case ISD::ROTR: {
1186       // Legalizing shifts/rotates requires adjusting the shift amount
1187       // to the appropriate width.
1188       SDValue Op0 = Node->getOperand(0);
1189       SDValue Op1 = Node->getOperand(1);
1190       if (!Op1.getValueType().isVector()) {
1191         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op1);
1192         // The getShiftAmountOperand() may create a new operand node or
1193         // return the existing one. If new operand is created we need
1194         // to update the parent node.
1195         // Do not try to legalize SAO here! It will be automatically legalized
1196         // in the next round.
1197         if (SAO != Op1)
1198           NewNode = DAG.UpdateNodeOperands(Node, Op0, SAO);
1199       }
1200     }
1201     break;
1202     case ISD::FSHL:
1203     case ISD::FSHR:
1204     case ISD::SRL_PARTS:
1205     case ISD::SRA_PARTS:
1206     case ISD::SHL_PARTS: {
1207       // Legalizing shifts/rotates requires adjusting the shift amount
1208       // to the appropriate width.
1209       SDValue Op0 = Node->getOperand(0);
1210       SDValue Op1 = Node->getOperand(1);
1211       SDValue Op2 = Node->getOperand(2);
1212       if (!Op2.getValueType().isVector()) {
1213         SDValue SAO = DAG.getShiftAmountOperand(Op0.getValueType(), Op2);
1214         // The getShiftAmountOperand() may create a new operand node or
1215         // return the existing one. If new operand is created we need
1216         // to update the parent node.
1217         if (SAO != Op2)
1218           NewNode = DAG.UpdateNodeOperands(Node, Op0, Op1, SAO);
1219       }
1220       break;
1221     }
1222     }
1223 
1224     if (NewNode != Node) {
1225       ReplaceNode(Node, NewNode);
1226       Node = NewNode;
1227     }
1228     switch (Action) {
1229     case TargetLowering::Legal:
1230       LLVM_DEBUG(dbgs() << "Legal node: nothing to do\n");
1231       return;
1232     case TargetLowering::Custom:
1233       LLVM_DEBUG(dbgs() << "Trying custom legalization\n");
1234       // FIXME: The handling for custom lowering with multiple results is
1235       // a complete mess.
1236       if (SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG)) {
1237         if (!(Res.getNode() != Node || Res.getResNo() != 0))
1238           return;
1239 
1240         if (Node->getNumValues() == 1) {
1241           LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1242           // We can just directly replace this node with the lowered value.
1243           ReplaceNode(SDValue(Node, 0), Res);
1244           return;
1245         }
1246 
1247         SmallVector<SDValue, 8> ResultVals;
1248         for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
1249           ResultVals.push_back(Res.getValue(i));
1250         LLVM_DEBUG(dbgs() << "Successfully custom legalized node\n");
1251         ReplaceNode(Node, ResultVals.data());
1252         return;
1253       }
1254       LLVM_DEBUG(dbgs() << "Could not custom legalize node\n");
1255       LLVM_FALLTHROUGH;
1256     case TargetLowering::Expand:
1257       if (ExpandNode(Node))
1258         return;
1259       LLVM_FALLTHROUGH;
1260     case TargetLowering::LibCall:
1261       ConvertNodeToLibcall(Node);
1262       return;
1263     case TargetLowering::Promote:
1264       PromoteNode(Node);
1265       return;
1266     }
1267   }
1268 
1269   switch (Node->getOpcode()) {
1270   default:
1271 #ifndef NDEBUG
1272     dbgs() << "NODE: ";
1273     Node->dump( &DAG);
1274     dbgs() << "\n";
1275 #endif
1276     llvm_unreachable("Do not know how to legalize this operator!");
1277 
1278   case ISD::CALLSEQ_START:
1279   case ISD::CALLSEQ_END:
1280     break;
1281   case ISD::LOAD:
1282     return LegalizeLoadOps(Node);
1283   case ISD::STORE:
1284     return LegalizeStoreOps(Node);
1285   }
1286 }
1287 
1288 SDValue SelectionDAGLegalize::ExpandExtractFromVectorThroughStack(SDValue Op) {
1289   SDValue Vec = Op.getOperand(0);
1290   SDValue Idx = Op.getOperand(1);
1291   SDLoc dl(Op);
1292 
1293   // Before we generate a new store to a temporary stack slot, see if there is
1294   // already one that we can use. There often is because when we scalarize
1295   // vector operations (using SelectionDAG::UnrollVectorOp for example) a whole
1296   // series of EXTRACT_VECTOR_ELT nodes are generated, one for each element in
1297   // the vector. If all are expanded here, we don't want one store per vector
1298   // element.
1299 
1300   // Caches for hasPredecessorHelper
1301   SmallPtrSet<const SDNode *, 32> Visited;
1302   SmallVector<const SDNode *, 16> Worklist;
1303   Visited.insert(Op.getNode());
1304   Worklist.push_back(Idx.getNode());
1305   SDValue StackPtr, Ch;
1306   for (SDNode::use_iterator UI = Vec.getNode()->use_begin(),
1307        UE = Vec.getNode()->use_end(); UI != UE; ++UI) {
1308     SDNode *User = *UI;
1309     if (StoreSDNode *ST = dyn_cast<StoreSDNode>(User)) {
1310       if (ST->isIndexed() || ST->isTruncatingStore() ||
1311           ST->getValue() != Vec)
1312         continue;
1313 
1314       // Make sure that nothing else could have stored into the destination of
1315       // this store.
1316       if (!ST->getChain().reachesChainWithoutSideEffects(DAG.getEntryNode()))
1317         continue;
1318 
1319       // If the index is dependent on the store we will introduce a cycle when
1320       // creating the load (the load uses the index, and by replacing the chain
1321       // we will make the index dependent on the load). Also, the store might be
1322       // dependent on the extractelement and introduce a cycle when creating
1323       // the load.
1324       if (SDNode::hasPredecessorHelper(ST, Visited, Worklist) ||
1325           ST->hasPredecessor(Op.getNode()))
1326         continue;
1327 
1328       StackPtr = ST->getBasePtr();
1329       Ch = SDValue(ST, 0);
1330       break;
1331     }
1332   }
1333 
1334   EVT VecVT = Vec.getValueType();
1335 
1336   if (!Ch.getNode()) {
1337     // Store the value to a temporary stack slot, then LOAD the returned part.
1338     StackPtr = DAG.CreateStackTemporary(VecVT);
1339     Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr,
1340                       MachinePointerInfo());
1341   }
1342 
1343   StackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1344 
1345   SDValue NewLoad;
1346 
1347   if (Op.getValueType().isVector())
1348     NewLoad =
1349         DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, MachinePointerInfo());
1350   else
1351     NewLoad = DAG.getExtLoad(ISD::EXTLOAD, dl, Op.getValueType(), Ch, StackPtr,
1352                              MachinePointerInfo(),
1353                              VecVT.getVectorElementType());
1354 
1355   // Replace the chain going out of the store, by the one out of the load.
1356   DAG.ReplaceAllUsesOfValueWith(Ch, SDValue(NewLoad.getNode(), 1));
1357 
1358   // We introduced a cycle though, so update the loads operands, making sure
1359   // to use the original store's chain as an incoming chain.
1360   SmallVector<SDValue, 6> NewLoadOperands(NewLoad->op_begin(),
1361                                           NewLoad->op_end());
1362   NewLoadOperands[0] = Ch;
1363   NewLoad =
1364       SDValue(DAG.UpdateNodeOperands(NewLoad.getNode(), NewLoadOperands), 0);
1365   return NewLoad;
1366 }
1367 
1368 SDValue SelectionDAGLegalize::ExpandInsertToVectorThroughStack(SDValue Op) {
1369   assert(Op.getValueType().isVector() && "Non-vector insert subvector!");
1370 
1371   SDValue Vec  = Op.getOperand(0);
1372   SDValue Part = Op.getOperand(1);
1373   SDValue Idx  = Op.getOperand(2);
1374   SDLoc dl(Op);
1375 
1376   // Store the value to a temporary stack slot, then LOAD the returned part.
1377   EVT VecVT = Vec.getValueType();
1378   SDValue StackPtr = DAG.CreateStackTemporary(VecVT);
1379   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1380   MachinePointerInfo PtrInfo =
1381       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1382 
1383   // First store the whole vector.
1384   SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, PtrInfo);
1385 
1386   // Then store the inserted part.
1387   SDValue SubStackPtr = TLI.getVectorElementPointer(DAG, StackPtr, VecVT, Idx);
1388 
1389   // Store the subvector.
1390   Ch = DAG.getStore(
1391       Ch, dl, Part, SubStackPtr,
1392       MachinePointerInfo::getUnknownStack(DAG.getMachineFunction()));
1393 
1394   // Finally, load the updated vector.
1395   return DAG.getLoad(Op.getValueType(), dl, Ch, StackPtr, PtrInfo);
1396 }
1397 
1398 SDValue SelectionDAGLegalize::ExpandVectorBuildThroughStack(SDNode* Node) {
1399   assert((Node->getOpcode() == ISD::BUILD_VECTOR ||
1400           Node->getOpcode() == ISD::CONCAT_VECTORS) &&
1401          "Unexpected opcode!");
1402 
1403   // We can't handle this case efficiently.  Allocate a sufficiently
1404   // aligned object on the stack, store each operand into it, then load
1405   // the result as a vector.
1406   // Create the stack frame object.
1407   EVT VT = Node->getValueType(0);
1408   EVT MemVT = isa<BuildVectorSDNode>(Node) ? VT.getVectorElementType()
1409                                            : Node->getOperand(0).getValueType();
1410   SDLoc dl(Node);
1411   SDValue FIPtr = DAG.CreateStackTemporary(VT);
1412   int FI = cast<FrameIndexSDNode>(FIPtr.getNode())->getIndex();
1413   MachinePointerInfo PtrInfo =
1414       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI);
1415 
1416   // Emit a store of each element to the stack slot.
1417   SmallVector<SDValue, 8> Stores;
1418   unsigned TypeByteSize = MemVT.getSizeInBits() / 8;
1419   assert(TypeByteSize > 0 && "Vector element type too small for stack store!");
1420 
1421   // If the destination vector element type of a BUILD_VECTOR is narrower than
1422   // the source element type, only store the bits necessary.
1423   bool Truncate = isa<BuildVectorSDNode>(Node) &&
1424                   MemVT.bitsLT(Node->getOperand(0).getValueType());
1425 
1426   // Store (in the right endianness) the elements to memory.
1427   for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
1428     // Ignore undef elements.
1429     if (Node->getOperand(i).isUndef()) continue;
1430 
1431     unsigned Offset = TypeByteSize*i;
1432 
1433     SDValue Idx = DAG.getMemBasePlusOffset(FIPtr, TypeSize::Fixed(Offset), dl);
1434 
1435     if (Truncate)
1436       Stores.push_back(DAG.getTruncStore(DAG.getEntryNode(), dl,
1437                                          Node->getOperand(i), Idx,
1438                                          PtrInfo.getWithOffset(Offset), MemVT));
1439     else
1440       Stores.push_back(DAG.getStore(DAG.getEntryNode(), dl, Node->getOperand(i),
1441                                     Idx, PtrInfo.getWithOffset(Offset)));
1442   }
1443 
1444   SDValue StoreChain;
1445   if (!Stores.empty())    // Not all undef elements?
1446     StoreChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Stores);
1447   else
1448     StoreChain = DAG.getEntryNode();
1449 
1450   // Result is a load from the stack slot.
1451   return DAG.getLoad(VT, dl, StoreChain, FIPtr, PtrInfo);
1452 }
1453 
1454 /// Bitcast a floating-point value to an integer value. Only bitcast the part
1455 /// containing the sign bit if the target has no integer value capable of
1456 /// holding all bits of the floating-point value.
1457 void SelectionDAGLegalize::getSignAsIntValue(FloatSignAsInt &State,
1458                                              const SDLoc &DL,
1459                                              SDValue Value) const {
1460   EVT FloatVT = Value.getValueType();
1461   unsigned NumBits = FloatVT.getSizeInBits();
1462   State.FloatVT = FloatVT;
1463   EVT IVT = EVT::getIntegerVT(*DAG.getContext(), NumBits);
1464   // Convert to an integer of the same size.
1465   if (TLI.isTypeLegal(IVT)) {
1466     State.IntValue = DAG.getNode(ISD::BITCAST, DL, IVT, Value);
1467     State.SignMask = APInt::getSignMask(NumBits);
1468     State.SignBit = NumBits - 1;
1469     return;
1470   }
1471 
1472   auto &DataLayout = DAG.getDataLayout();
1473   // Store the float to memory, then load the sign part out as an integer.
1474   MVT LoadTy = TLI.getRegisterType(*DAG.getContext(), MVT::i8);
1475   // First create a temporary that is aligned for both the load and store.
1476   SDValue StackPtr = DAG.CreateStackTemporary(FloatVT, LoadTy);
1477   int FI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
1478   // Then store the float to it.
1479   State.FloatPtr = StackPtr;
1480   MachineFunction &MF = DAG.getMachineFunction();
1481   State.FloatPointerInfo = MachinePointerInfo::getFixedStack(MF, FI);
1482   State.Chain = DAG.getStore(DAG.getEntryNode(), DL, Value, State.FloatPtr,
1483                              State.FloatPointerInfo);
1484 
1485   SDValue IntPtr;
1486   if (DataLayout.isBigEndian()) {
1487     assert(FloatVT.isByteSized() && "Unsupported floating point type!");
1488     // Load out a legal integer with the same sign bit as the float.
1489     IntPtr = StackPtr;
1490     State.IntPointerInfo = State.FloatPointerInfo;
1491   } else {
1492     // Advance the pointer so that the loaded byte will contain the sign bit.
1493     unsigned ByteOffset = (FloatVT.getSizeInBits() / 8) - 1;
1494     IntPtr =
1495         DAG.getMemBasePlusOffset(StackPtr, TypeSize::Fixed(ByteOffset), DL);
1496     State.IntPointerInfo = MachinePointerInfo::getFixedStack(MF, FI,
1497                                                              ByteOffset);
1498   }
1499 
1500   State.IntPtr = IntPtr;
1501   State.IntValue = DAG.getExtLoad(ISD::EXTLOAD, DL, LoadTy, State.Chain, IntPtr,
1502                                   State.IntPointerInfo, MVT::i8);
1503   State.SignMask = APInt::getOneBitSet(LoadTy.getSizeInBits(), 7);
1504   State.SignBit = 7;
1505 }
1506 
1507 /// Replace the integer value produced by getSignAsIntValue() with a new value
1508 /// and cast the result back to a floating-point type.
1509 SDValue SelectionDAGLegalize::modifySignAsInt(const FloatSignAsInt &State,
1510                                               const SDLoc &DL,
1511                                               SDValue NewIntValue) const {
1512   if (!State.Chain)
1513     return DAG.getNode(ISD::BITCAST, DL, State.FloatVT, NewIntValue);
1514 
1515   // Override the part containing the sign bit in the value stored on the stack.
1516   SDValue Chain = DAG.getTruncStore(State.Chain, DL, NewIntValue, State.IntPtr,
1517                                     State.IntPointerInfo, MVT::i8);
1518   return DAG.getLoad(State.FloatVT, DL, Chain, State.FloatPtr,
1519                      State.FloatPointerInfo);
1520 }
1521 
1522 SDValue SelectionDAGLegalize::ExpandFCOPYSIGN(SDNode *Node) const {
1523   SDLoc DL(Node);
1524   SDValue Mag = Node->getOperand(0);
1525   SDValue Sign = Node->getOperand(1);
1526 
1527   // Get sign bit into an integer value.
1528   FloatSignAsInt SignAsInt;
1529   getSignAsIntValue(SignAsInt, DL, Sign);
1530 
1531   EVT IntVT = SignAsInt.IntValue.getValueType();
1532   SDValue SignMask = DAG.getConstant(SignAsInt.SignMask, DL, IntVT);
1533   SDValue SignBit = DAG.getNode(ISD::AND, DL, IntVT, SignAsInt.IntValue,
1534                                 SignMask);
1535 
1536   // If FABS is legal transform FCOPYSIGN(x, y) => sign(x) ? -FABS(x) : FABS(X)
1537   EVT FloatVT = Mag.getValueType();
1538   if (TLI.isOperationLegalOrCustom(ISD::FABS, FloatVT) &&
1539       TLI.isOperationLegalOrCustom(ISD::FNEG, FloatVT)) {
1540     SDValue AbsValue = DAG.getNode(ISD::FABS, DL, FloatVT, Mag);
1541     SDValue NegValue = DAG.getNode(ISD::FNEG, DL, FloatVT, AbsValue);
1542     SDValue Cond = DAG.getSetCC(DL, getSetCCResultType(IntVT), SignBit,
1543                                 DAG.getConstant(0, DL, IntVT), ISD::SETNE);
1544     return DAG.getSelect(DL, FloatVT, Cond, NegValue, AbsValue);
1545   }
1546 
1547   // Transform Mag value to integer, and clear the sign bit.
1548   FloatSignAsInt MagAsInt;
1549   getSignAsIntValue(MagAsInt, DL, Mag);
1550   EVT MagVT = MagAsInt.IntValue.getValueType();
1551   SDValue ClearSignMask = DAG.getConstant(~MagAsInt.SignMask, DL, MagVT);
1552   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, MagVT, MagAsInt.IntValue,
1553                                     ClearSignMask);
1554 
1555   // Get the signbit at the right position for MagAsInt.
1556   int ShiftAmount = SignAsInt.SignBit - MagAsInt.SignBit;
1557   EVT ShiftVT = IntVT;
1558   if (SignBit.getValueSizeInBits() < ClearedSign.getValueSizeInBits()) {
1559     SignBit = DAG.getNode(ISD::ZERO_EXTEND, DL, MagVT, SignBit);
1560     ShiftVT = MagVT;
1561   }
1562   if (ShiftAmount > 0) {
1563     SDValue ShiftCnst = DAG.getConstant(ShiftAmount, DL, ShiftVT);
1564     SignBit = DAG.getNode(ISD::SRL, DL, ShiftVT, SignBit, ShiftCnst);
1565   } else if (ShiftAmount < 0) {
1566     SDValue ShiftCnst = DAG.getConstant(-ShiftAmount, DL, ShiftVT);
1567     SignBit = DAG.getNode(ISD::SHL, DL, ShiftVT, SignBit, ShiftCnst);
1568   }
1569   if (SignBit.getValueSizeInBits() > ClearedSign.getValueSizeInBits()) {
1570     SignBit = DAG.getNode(ISD::TRUNCATE, DL, MagVT, SignBit);
1571   }
1572 
1573   // Store the part with the modified sign and convert back to float.
1574   SDValue CopiedSign = DAG.getNode(ISD::OR, DL, MagVT, ClearedSign, SignBit);
1575   return modifySignAsInt(MagAsInt, DL, CopiedSign);
1576 }
1577 
1578 SDValue SelectionDAGLegalize::ExpandFNEG(SDNode *Node) const {
1579   // Get the sign bit as an integer.
1580   SDLoc DL(Node);
1581   FloatSignAsInt SignAsInt;
1582   getSignAsIntValue(SignAsInt, DL, Node->getOperand(0));
1583   EVT IntVT = SignAsInt.IntValue.getValueType();
1584 
1585   // Flip the sign.
1586   SDValue SignMask = DAG.getConstant(SignAsInt.SignMask, DL, IntVT);
1587   SDValue SignFlip =
1588       DAG.getNode(ISD::XOR, DL, IntVT, SignAsInt.IntValue, SignMask);
1589 
1590   // Convert back to float.
1591   return modifySignAsInt(SignAsInt, DL, SignFlip);
1592 }
1593 
1594 SDValue SelectionDAGLegalize::ExpandFABS(SDNode *Node) const {
1595   SDLoc DL(Node);
1596   SDValue Value = Node->getOperand(0);
1597 
1598   // Transform FABS(x) => FCOPYSIGN(x, 0.0) if FCOPYSIGN is legal.
1599   EVT FloatVT = Value.getValueType();
1600   if (TLI.isOperationLegalOrCustom(ISD::FCOPYSIGN, FloatVT)) {
1601     SDValue Zero = DAG.getConstantFP(0.0, DL, FloatVT);
1602     return DAG.getNode(ISD::FCOPYSIGN, DL, FloatVT, Value, Zero);
1603   }
1604 
1605   // Transform value to integer, clear the sign bit and transform back.
1606   FloatSignAsInt ValueAsInt;
1607   getSignAsIntValue(ValueAsInt, DL, Value);
1608   EVT IntVT = ValueAsInt.IntValue.getValueType();
1609   SDValue ClearSignMask = DAG.getConstant(~ValueAsInt.SignMask, DL, IntVT);
1610   SDValue ClearedSign = DAG.getNode(ISD::AND, DL, IntVT, ValueAsInt.IntValue,
1611                                     ClearSignMask);
1612   return modifySignAsInt(ValueAsInt, DL, ClearedSign);
1613 }
1614 
1615 void SelectionDAGLegalize::ExpandDYNAMIC_STACKALLOC(SDNode* Node,
1616                                            SmallVectorImpl<SDValue> &Results) {
1617   unsigned SPReg = TLI.getStackPointerRegisterToSaveRestore();
1618   assert(SPReg && "Target cannot require DYNAMIC_STACKALLOC expansion and"
1619           " not tell us which reg is the stack pointer!");
1620   SDLoc dl(Node);
1621   EVT VT = Node->getValueType(0);
1622   SDValue Tmp1 = SDValue(Node, 0);
1623   SDValue Tmp2 = SDValue(Node, 1);
1624   SDValue Tmp3 = Node->getOperand(2);
1625   SDValue Chain = Tmp1.getOperand(0);
1626 
1627   // Chain the dynamic stack allocation so that it doesn't modify the stack
1628   // pointer when other instructions are using the stack.
1629   Chain = DAG.getCALLSEQ_START(Chain, 0, 0, dl);
1630 
1631   SDValue Size  = Tmp2.getOperand(1);
1632   SDValue SP = DAG.getCopyFromReg(Chain, dl, SPReg, VT);
1633   Chain = SP.getValue(1);
1634   Align Alignment = cast<ConstantSDNode>(Tmp3)->getAlignValue();
1635   const TargetFrameLowering *TFL = DAG.getSubtarget().getFrameLowering();
1636   unsigned Opc =
1637     TFL->getStackGrowthDirection() == TargetFrameLowering::StackGrowsUp ?
1638     ISD::ADD : ISD::SUB;
1639 
1640   Align StackAlign = TFL->getStackAlign();
1641   Tmp1 = DAG.getNode(Opc, dl, VT, SP, Size);       // Value
1642   if (Alignment > StackAlign)
1643     Tmp1 = DAG.getNode(ISD::AND, dl, VT, Tmp1,
1644                        DAG.getConstant(-Alignment.value(), dl, VT));
1645   Chain = DAG.getCopyToReg(Chain, dl, SPReg, Tmp1);     // Output chain
1646 
1647   Tmp2 = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(0, dl, true),
1648                             DAG.getIntPtrConstant(0, dl, true), SDValue(), dl);
1649 
1650   Results.push_back(Tmp1);
1651   Results.push_back(Tmp2);
1652 }
1653 
1654 /// Legalize a SETCC with given LHS and RHS and condition code CC on the current
1655 /// target.
1656 ///
1657 /// If the SETCC has been legalized using AND / OR, then the legalized node
1658 /// will be stored in LHS. RHS and CC will be set to SDValue(). NeedInvert
1659 /// will be set to false.
1660 ///
1661 /// If the SETCC has been legalized by using getSetCCSwappedOperands(),
1662 /// then the values of LHS and RHS will be swapped, CC will be set to the
1663 /// new condition, and NeedInvert will be set to false.
1664 ///
1665 /// If the SETCC has been legalized using the inverse condcode, then LHS and
1666 /// RHS will be unchanged, CC will set to the inverted condcode, and NeedInvert
1667 /// will be set to true. The caller must invert the result of the SETCC with
1668 /// SelectionDAG::getLogicalNOT() or take equivalent action to swap the effect
1669 /// of a true/false result.
1670 ///
1671 /// \returns true if the SetCC has been legalized, false if it hasn't.
1672 bool SelectionDAGLegalize::LegalizeSetCCCondCode(
1673     EVT VT, SDValue &LHS, SDValue &RHS, SDValue &CC, bool &NeedInvert,
1674     const SDLoc &dl, SDValue &Chain, bool IsSignaling) {
1675   MVT OpVT = LHS.getSimpleValueType();
1676   ISD::CondCode CCCode = cast<CondCodeSDNode>(CC)->get();
1677   NeedInvert = false;
1678   switch (TLI.getCondCodeAction(CCCode, OpVT)) {
1679   default: llvm_unreachable("Unknown condition code action!");
1680   case TargetLowering::Legal:
1681     // Nothing to do.
1682     break;
1683   case TargetLowering::Expand: {
1684     ISD::CondCode InvCC = ISD::getSetCCSwappedOperands(CCCode);
1685     if (TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1686       std::swap(LHS, RHS);
1687       CC = DAG.getCondCode(InvCC);
1688       return true;
1689     }
1690     // Swapping operands didn't work. Try inverting the condition.
1691     bool NeedSwap = false;
1692     InvCC = getSetCCInverse(CCCode, OpVT);
1693     if (!TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1694       // If inverting the condition is not enough, try swapping operands
1695       // on top of it.
1696       InvCC = ISD::getSetCCSwappedOperands(InvCC);
1697       NeedSwap = true;
1698     }
1699     if (TLI.isCondCodeLegalOrCustom(InvCC, OpVT)) {
1700       CC = DAG.getCondCode(InvCC);
1701       NeedInvert = true;
1702       if (NeedSwap)
1703         std::swap(LHS, RHS);
1704       return true;
1705     }
1706 
1707     ISD::CondCode CC1 = ISD::SETCC_INVALID, CC2 = ISD::SETCC_INVALID;
1708     unsigned Opc = 0;
1709     switch (CCCode) {
1710     default: llvm_unreachable("Don't know how to expand this condition!");
1711     case ISD::SETO:
1712         assert(TLI.isCondCodeLegal(ISD::SETOEQ, OpVT)
1713             && "If SETO is expanded, SETOEQ must be legal!");
1714         CC1 = ISD::SETOEQ; CC2 = ISD::SETOEQ; Opc = ISD::AND; break;
1715     case ISD::SETUO:
1716         assert(TLI.isCondCodeLegal(ISD::SETUNE, OpVT)
1717             && "If SETUO is expanded, SETUNE must be legal!");
1718         CC1 = ISD::SETUNE; CC2 = ISD::SETUNE; Opc = ISD::OR;  break;
1719     case ISD::SETOEQ:
1720     case ISD::SETOGT:
1721     case ISD::SETOGE:
1722     case ISD::SETOLT:
1723     case ISD::SETOLE:
1724     case ISD::SETONE:
1725     case ISD::SETUEQ:
1726     case ISD::SETUNE:
1727     case ISD::SETUGT:
1728     case ISD::SETUGE:
1729     case ISD::SETULT:
1730     case ISD::SETULE:
1731         // If we are floating point, assign and break, otherwise fall through.
1732         if (!OpVT.isInteger()) {
1733           // We can use the 4th bit to tell if we are the unordered
1734           // or ordered version of the opcode.
1735           CC2 = ((unsigned)CCCode & 0x8U) ? ISD::SETUO : ISD::SETO;
1736           Opc = ((unsigned)CCCode & 0x8U) ? ISD::OR : ISD::AND;
1737           CC1 = (ISD::CondCode)(((int)CCCode & 0x7) | 0x10);
1738           break;
1739         }
1740         // Fallthrough if we are unsigned integer.
1741         LLVM_FALLTHROUGH;
1742     case ISD::SETLE:
1743     case ISD::SETGT:
1744     case ISD::SETGE:
1745     case ISD::SETLT:
1746     case ISD::SETNE:
1747     case ISD::SETEQ:
1748       // If all combinations of inverting the condition and swapping operands
1749       // didn't work then we have no means to expand the condition.
1750       llvm_unreachable("Don't know how to expand this condition!");
1751     }
1752 
1753     SDValue SetCC1, SetCC2;
1754     if (CCCode != ISD::SETO && CCCode != ISD::SETUO) {
1755       // If we aren't the ordered or unorder operation,
1756       // then the pattern is (LHS CC1 RHS) Opc (LHS CC2 RHS).
1757       SetCC1 = DAG.getSetCC(dl, VT, LHS, RHS, CC1, Chain,
1758                             IsSignaling);
1759       SetCC2 = DAG.getSetCC(dl, VT, LHS, RHS, CC2, Chain,
1760                             IsSignaling);
1761     } else {
1762       // Otherwise, the pattern is (LHS CC1 LHS) Opc (RHS CC2 RHS)
1763       SetCC1 = DAG.getSetCC(dl, VT, LHS, LHS, CC1, Chain,
1764                             IsSignaling);
1765       SetCC2 = DAG.getSetCC(dl, VT, RHS, RHS, CC2, Chain,
1766                             IsSignaling);
1767     }
1768     if (Chain)
1769       Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, SetCC1.getValue(1),
1770                           SetCC2.getValue(1));
1771     LHS = DAG.getNode(Opc, dl, VT, SetCC1, SetCC2);
1772     RHS = SDValue();
1773     CC  = SDValue();
1774     return true;
1775   }
1776   }
1777   return false;
1778 }
1779 
1780 /// Emit a store/load combination to the stack.  This stores
1781 /// SrcOp to a stack slot of type SlotVT, truncating it if needed.  It then does
1782 /// a load from the stack slot to DestVT, extending it if needed.
1783 /// The resultant code need not be legal.
1784 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1785                                                EVT DestVT, const SDLoc &dl) {
1786   return EmitStackConvert(SrcOp, SlotVT, DestVT, dl, DAG.getEntryNode());
1787 }
1788 
1789 SDValue SelectionDAGLegalize::EmitStackConvert(SDValue SrcOp, EVT SlotVT,
1790                                                EVT DestVT, const SDLoc &dl,
1791                                                SDValue Chain) {
1792   // Create the stack frame object.
1793   Align SrcAlign = DAG.getDataLayout().getPrefTypeAlign(
1794       SrcOp.getValueType().getTypeForEVT(*DAG.getContext()));
1795   SDValue FIPtr = DAG.CreateStackTemporary(SlotVT.getStoreSize(), SrcAlign);
1796 
1797   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(FIPtr);
1798   int SPFI = StackPtrFI->getIndex();
1799   MachinePointerInfo PtrInfo =
1800       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI);
1801 
1802   unsigned SrcSize = SrcOp.getValueSizeInBits();
1803   unsigned SlotSize = SlotVT.getSizeInBits();
1804   unsigned DestSize = DestVT.getSizeInBits();
1805   Type *DestType = DestVT.getTypeForEVT(*DAG.getContext());
1806   Align DestAlign = DAG.getDataLayout().getPrefTypeAlign(DestType);
1807 
1808   // Emit a store to the stack slot.  Use a truncstore if the input value is
1809   // later than DestVT.
1810   SDValue Store;
1811 
1812   if (SrcSize > SlotSize)
1813     Store = DAG.getTruncStore(Chain, dl, SrcOp, FIPtr, PtrInfo,
1814                               SlotVT, SrcAlign);
1815   else {
1816     assert(SrcSize == SlotSize && "Invalid store");
1817     Store =
1818         DAG.getStore(Chain, dl, SrcOp, FIPtr, PtrInfo, SrcAlign);
1819   }
1820 
1821   // Result is a load from the stack slot.
1822   if (SlotSize == DestSize)
1823     return DAG.getLoad(DestVT, dl, Store, FIPtr, PtrInfo, DestAlign);
1824 
1825   assert(SlotSize < DestSize && "Unknown extension!");
1826   return DAG.getExtLoad(ISD::EXTLOAD, dl, DestVT, Store, FIPtr, PtrInfo, SlotVT,
1827                         DestAlign);
1828 }
1829 
1830 SDValue SelectionDAGLegalize::ExpandSCALAR_TO_VECTOR(SDNode *Node) {
1831   SDLoc dl(Node);
1832   // Create a vector sized/aligned stack slot, store the value to element #0,
1833   // then load the whole vector back out.
1834   SDValue StackPtr = DAG.CreateStackTemporary(Node->getValueType(0));
1835 
1836   FrameIndexSDNode *StackPtrFI = cast<FrameIndexSDNode>(StackPtr);
1837   int SPFI = StackPtrFI->getIndex();
1838 
1839   SDValue Ch = DAG.getTruncStore(
1840       DAG.getEntryNode(), dl, Node->getOperand(0), StackPtr,
1841       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI),
1842       Node->getValueType(0).getVectorElementType());
1843   return DAG.getLoad(
1844       Node->getValueType(0), dl, Ch, StackPtr,
1845       MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), SPFI));
1846 }
1847 
1848 static bool
1849 ExpandBVWithShuffles(SDNode *Node, SelectionDAG &DAG,
1850                      const TargetLowering &TLI, SDValue &Res) {
1851   unsigned NumElems = Node->getNumOperands();
1852   SDLoc dl(Node);
1853   EVT VT = Node->getValueType(0);
1854 
1855   // Try to group the scalars into pairs, shuffle the pairs together, then
1856   // shuffle the pairs of pairs together, etc. until the vector has
1857   // been built. This will work only if all of the necessary shuffle masks
1858   // are legal.
1859 
1860   // We do this in two phases; first to check the legality of the shuffles,
1861   // and next, assuming that all shuffles are legal, to create the new nodes.
1862   for (int Phase = 0; Phase < 2; ++Phase) {
1863     SmallVector<std::pair<SDValue, SmallVector<int, 16>>, 16> IntermedVals,
1864                                                               NewIntermedVals;
1865     for (unsigned i = 0; i < NumElems; ++i) {
1866       SDValue V = Node->getOperand(i);
1867       if (V.isUndef())
1868         continue;
1869 
1870       SDValue Vec;
1871       if (Phase)
1872         Vec = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, V);
1873       IntermedVals.push_back(std::make_pair(Vec, SmallVector<int, 16>(1, i)));
1874     }
1875 
1876     while (IntermedVals.size() > 2) {
1877       NewIntermedVals.clear();
1878       for (unsigned i = 0, e = (IntermedVals.size() & ~1u); i < e; i += 2) {
1879         // This vector and the next vector are shuffled together (simply to
1880         // append the one to the other).
1881         SmallVector<int, 16> ShuffleVec(NumElems, -1);
1882 
1883         SmallVector<int, 16> FinalIndices;
1884         FinalIndices.reserve(IntermedVals[i].second.size() +
1885                              IntermedVals[i+1].second.size());
1886 
1887         int k = 0;
1888         for (unsigned j = 0, f = IntermedVals[i].second.size(); j != f;
1889              ++j, ++k) {
1890           ShuffleVec[k] = j;
1891           FinalIndices.push_back(IntermedVals[i].second[j]);
1892         }
1893         for (unsigned j = 0, f = IntermedVals[i+1].second.size(); j != f;
1894              ++j, ++k) {
1895           ShuffleVec[k] = NumElems + j;
1896           FinalIndices.push_back(IntermedVals[i+1].second[j]);
1897         }
1898 
1899         SDValue Shuffle;
1900         if (Phase)
1901           Shuffle = DAG.getVectorShuffle(VT, dl, IntermedVals[i].first,
1902                                          IntermedVals[i+1].first,
1903                                          ShuffleVec);
1904         else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1905           return false;
1906         NewIntermedVals.push_back(
1907             std::make_pair(Shuffle, std::move(FinalIndices)));
1908       }
1909 
1910       // If we had an odd number of defined values, then append the last
1911       // element to the array of new vectors.
1912       if ((IntermedVals.size() & 1) != 0)
1913         NewIntermedVals.push_back(IntermedVals.back());
1914 
1915       IntermedVals.swap(NewIntermedVals);
1916     }
1917 
1918     assert(IntermedVals.size() <= 2 && IntermedVals.size() > 0 &&
1919            "Invalid number of intermediate vectors");
1920     SDValue Vec1 = IntermedVals[0].first;
1921     SDValue Vec2;
1922     if (IntermedVals.size() > 1)
1923       Vec2 = IntermedVals[1].first;
1924     else if (Phase)
1925       Vec2 = DAG.getUNDEF(VT);
1926 
1927     SmallVector<int, 16> ShuffleVec(NumElems, -1);
1928     for (unsigned i = 0, e = IntermedVals[0].second.size(); i != e; ++i)
1929       ShuffleVec[IntermedVals[0].second[i]] = i;
1930     for (unsigned i = 0, e = IntermedVals[1].second.size(); i != e; ++i)
1931       ShuffleVec[IntermedVals[1].second[i]] = NumElems + i;
1932 
1933     if (Phase)
1934       Res = DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
1935     else if (!TLI.isShuffleMaskLegal(ShuffleVec, VT))
1936       return false;
1937   }
1938 
1939   return true;
1940 }
1941 
1942 /// Expand a BUILD_VECTOR node on targets that don't
1943 /// support the operation, but do support the resultant vector type.
1944 SDValue SelectionDAGLegalize::ExpandBUILD_VECTOR(SDNode *Node) {
1945   unsigned NumElems = Node->getNumOperands();
1946   SDValue Value1, Value2;
1947   SDLoc dl(Node);
1948   EVT VT = Node->getValueType(0);
1949   EVT OpVT = Node->getOperand(0).getValueType();
1950   EVT EltVT = VT.getVectorElementType();
1951 
1952   // If the only non-undef value is the low element, turn this into a
1953   // SCALAR_TO_VECTOR node.  If this is { X, X, X, X }, determine X.
1954   bool isOnlyLowElement = true;
1955   bool MoreThanTwoValues = false;
1956   bool isConstant = true;
1957   for (unsigned i = 0; i < NumElems; ++i) {
1958     SDValue V = Node->getOperand(i);
1959     if (V.isUndef())
1960       continue;
1961     if (i > 0)
1962       isOnlyLowElement = false;
1963     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
1964       isConstant = false;
1965 
1966     if (!Value1.getNode()) {
1967       Value1 = V;
1968     } else if (!Value2.getNode()) {
1969       if (V != Value1)
1970         Value2 = V;
1971     } else if (V != Value1 && V != Value2) {
1972       MoreThanTwoValues = true;
1973     }
1974   }
1975 
1976   if (!Value1.getNode())
1977     return DAG.getUNDEF(VT);
1978 
1979   if (isOnlyLowElement)
1980     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Node->getOperand(0));
1981 
1982   // If all elements are constants, create a load from the constant pool.
1983   if (isConstant) {
1984     SmallVector<Constant*, 16> CV;
1985     for (unsigned i = 0, e = NumElems; i != e; ++i) {
1986       if (ConstantFPSDNode *V =
1987           dyn_cast<ConstantFPSDNode>(Node->getOperand(i))) {
1988         CV.push_back(const_cast<ConstantFP *>(V->getConstantFPValue()));
1989       } else if (ConstantSDNode *V =
1990                  dyn_cast<ConstantSDNode>(Node->getOperand(i))) {
1991         if (OpVT==EltVT)
1992           CV.push_back(const_cast<ConstantInt *>(V->getConstantIntValue()));
1993         else {
1994           // If OpVT and EltVT don't match, EltVT is not legal and the
1995           // element values have been promoted/truncated earlier.  Undo this;
1996           // we don't want a v16i8 to become a v16i32 for example.
1997           const ConstantInt *CI = V->getConstantIntValue();
1998           CV.push_back(ConstantInt::get(EltVT.getTypeForEVT(*DAG.getContext()),
1999                                         CI->getZExtValue()));
2000         }
2001       } else {
2002         assert(Node->getOperand(i).isUndef());
2003         Type *OpNTy = EltVT.getTypeForEVT(*DAG.getContext());
2004         CV.push_back(UndefValue::get(OpNTy));
2005       }
2006     }
2007     Constant *CP = ConstantVector::get(CV);
2008     SDValue CPIdx =
2009         DAG.getConstantPool(CP, TLI.getPointerTy(DAG.getDataLayout()));
2010     Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
2011     return DAG.getLoad(
2012         VT, dl, DAG.getEntryNode(), CPIdx,
2013         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
2014         Alignment);
2015   }
2016 
2017   SmallSet<SDValue, 16> DefinedValues;
2018   for (unsigned i = 0; i < NumElems; ++i) {
2019     if (Node->getOperand(i).isUndef())
2020       continue;
2021     DefinedValues.insert(Node->getOperand(i));
2022   }
2023 
2024   if (TLI.shouldExpandBuildVectorWithShuffles(VT, DefinedValues.size())) {
2025     if (!MoreThanTwoValues) {
2026       SmallVector<int, 8> ShuffleVec(NumElems, -1);
2027       for (unsigned i = 0; i < NumElems; ++i) {
2028         SDValue V = Node->getOperand(i);
2029         if (V.isUndef())
2030           continue;
2031         ShuffleVec[i] = V == Value1 ? 0 : NumElems;
2032       }
2033       if (TLI.isShuffleMaskLegal(ShuffleVec, Node->getValueType(0))) {
2034         // Get the splatted value into the low element of a vector register.
2035         SDValue Vec1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value1);
2036         SDValue Vec2;
2037         if (Value2.getNode())
2038           Vec2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value2);
2039         else
2040           Vec2 = DAG.getUNDEF(VT);
2041 
2042         // Return shuffle(LowValVec, undef, <0,0,0,0>)
2043         return DAG.getVectorShuffle(VT, dl, Vec1, Vec2, ShuffleVec);
2044       }
2045     } else {
2046       SDValue Res;
2047       if (ExpandBVWithShuffles(Node, DAG, TLI, Res))
2048         return Res;
2049     }
2050   }
2051 
2052   // Otherwise, we can't handle this case efficiently.
2053   return ExpandVectorBuildThroughStack(Node);
2054 }
2055 
2056 SDValue SelectionDAGLegalize::ExpandSPLAT_VECTOR(SDNode *Node) {
2057   SDLoc DL(Node);
2058   EVT VT = Node->getValueType(0);
2059   SDValue SplatVal = Node->getOperand(0);
2060 
2061   return DAG.getSplatBuildVector(VT, DL, SplatVal);
2062 }
2063 
2064 // Expand a node into a call to a libcall.  If the result value
2065 // does not fit into a register, return the lo part and set the hi part to the
2066 // by-reg argument.  If it does fit into a single register, return the result
2067 // and leave the Hi part unset.
2068 SDValue SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
2069                                             bool isSigned) {
2070   TargetLowering::ArgListTy Args;
2071   TargetLowering::ArgListEntry Entry;
2072   for (const SDValue &Op : Node->op_values()) {
2073     EVT ArgVT = Op.getValueType();
2074     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2075     Entry.Node = Op;
2076     Entry.Ty = ArgTy;
2077     Entry.IsSExt = TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2078     Entry.IsZExt = !TLI.shouldSignExtendTypeInLibCall(ArgVT, isSigned);
2079     Args.push_back(Entry);
2080   }
2081   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2082                                          TLI.getPointerTy(DAG.getDataLayout()));
2083 
2084   EVT RetVT = Node->getValueType(0);
2085   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2086 
2087   // By default, the input chain to this libcall is the entry node of the
2088   // function. If the libcall is going to be emitted as a tail call then
2089   // TLI.isUsedByReturnOnly will change it to the right chain if the return
2090   // node which is being folded has a non-entry input chain.
2091   SDValue InChain = DAG.getEntryNode();
2092 
2093   // isTailCall may be true since the callee does not reference caller stack
2094   // frame. Check if it's in the right position and that the return types match.
2095   SDValue TCChain = InChain;
2096   const Function &F = DAG.getMachineFunction().getFunction();
2097   bool isTailCall =
2098       TLI.isInTailCallPosition(DAG, Node, TCChain) &&
2099       (RetTy == F.getReturnType() || F.getReturnType()->isVoidTy());
2100   if (isTailCall)
2101     InChain = TCChain;
2102 
2103   TargetLowering::CallLoweringInfo CLI(DAG);
2104   bool signExtend = TLI.shouldSignExtendTypeInLibCall(RetVT, isSigned);
2105   CLI.setDebugLoc(SDLoc(Node))
2106       .setChain(InChain)
2107       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2108                     std::move(Args))
2109       .setTailCall(isTailCall)
2110       .setSExtResult(signExtend)
2111       .setZExtResult(!signExtend)
2112       .setIsPostTypeLegalization(true);
2113 
2114   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2115 
2116   if (!CallInfo.second.getNode()) {
2117     LLVM_DEBUG(dbgs() << "Created tailcall: "; DAG.getRoot().dump(&DAG));
2118     // It's a tailcall, return the chain (which is the DAG root).
2119     return DAG.getRoot();
2120   }
2121 
2122   LLVM_DEBUG(dbgs() << "Created libcall: "; CallInfo.first.dump(&DAG));
2123   return CallInfo.first;
2124 }
2125 
2126 void SelectionDAGLegalize::ExpandFPLibCall(SDNode* Node,
2127                                            RTLIB::Libcall Call_F32,
2128                                            RTLIB::Libcall Call_F64,
2129                                            RTLIB::Libcall Call_F80,
2130                                            RTLIB::Libcall Call_F128,
2131                                            RTLIB::Libcall Call_PPCF128,
2132                                            SmallVectorImpl<SDValue> &Results) {
2133   RTLIB::Libcall LC;
2134   switch (Node->getSimpleValueType(0).SimpleTy) {
2135   default: llvm_unreachable("Unexpected request for libcall!");
2136   case MVT::f32: LC = Call_F32; break;
2137   case MVT::f64: LC = Call_F64; break;
2138   case MVT::f80: LC = Call_F80; break;
2139   case MVT::f128: LC = Call_F128; break;
2140   case MVT::ppcf128: LC = Call_PPCF128; break;
2141   }
2142 
2143   if (Node->isStrictFPOpcode()) {
2144     EVT RetVT = Node->getValueType(0);
2145     SmallVector<SDValue, 4> Ops(Node->op_begin() + 1, Node->op_end());
2146     TargetLowering::MakeLibCallOptions CallOptions;
2147     // FIXME: This doesn't support tail calls.
2148     std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RetVT,
2149                                                       Ops, CallOptions,
2150                                                       SDLoc(Node),
2151                                                       Node->getOperand(0));
2152     Results.push_back(Tmp.first);
2153     Results.push_back(Tmp.second);
2154   } else {
2155     SDValue Tmp = ExpandLibCall(LC, Node, false);
2156     Results.push_back(Tmp);
2157   }
2158 }
2159 
2160 SDValue SelectionDAGLegalize::ExpandIntLibCall(SDNode* Node, bool isSigned,
2161                                                RTLIB::Libcall Call_I8,
2162                                                RTLIB::Libcall Call_I16,
2163                                                RTLIB::Libcall Call_I32,
2164                                                RTLIB::Libcall Call_I64,
2165                                                RTLIB::Libcall Call_I128) {
2166   RTLIB::Libcall LC;
2167   switch (Node->getSimpleValueType(0).SimpleTy) {
2168   default: llvm_unreachable("Unexpected request for libcall!");
2169   case MVT::i8:   LC = Call_I8; break;
2170   case MVT::i16:  LC = Call_I16; break;
2171   case MVT::i32:  LC = Call_I32; break;
2172   case MVT::i64:  LC = Call_I64; break;
2173   case MVT::i128: LC = Call_I128; break;
2174   }
2175   return ExpandLibCall(LC, Node, isSigned);
2176 }
2177 
2178 /// Expand the node to a libcall based on first argument type (for instance
2179 /// lround and its variant).
2180 void SelectionDAGLegalize::ExpandArgFPLibCall(SDNode* Node,
2181                                             RTLIB::Libcall Call_F32,
2182                                             RTLIB::Libcall Call_F64,
2183                                             RTLIB::Libcall Call_F80,
2184                                             RTLIB::Libcall Call_F128,
2185                                             RTLIB::Libcall Call_PPCF128,
2186                                             SmallVectorImpl<SDValue> &Results) {
2187   EVT InVT = Node->getOperand(Node->isStrictFPOpcode() ? 1 : 0).getValueType();
2188 
2189   RTLIB::Libcall LC;
2190   switch (InVT.getSimpleVT().SimpleTy) {
2191   default: llvm_unreachable("Unexpected request for libcall!");
2192   case MVT::f32:     LC = Call_F32; break;
2193   case MVT::f64:     LC = Call_F64; break;
2194   case MVT::f80:     LC = Call_F80; break;
2195   case MVT::f128:    LC = Call_F128; break;
2196   case MVT::ppcf128: LC = Call_PPCF128; break;
2197   }
2198 
2199   if (Node->isStrictFPOpcode()) {
2200     EVT RetVT = Node->getValueType(0);
2201     SmallVector<SDValue, 4> Ops(Node->op_begin() + 1, Node->op_end());
2202     TargetLowering::MakeLibCallOptions CallOptions;
2203     // FIXME: This doesn't support tail calls.
2204     std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RetVT,
2205                                                       Ops, CallOptions,
2206                                                       SDLoc(Node),
2207                                                       Node->getOperand(0));
2208     Results.push_back(Tmp.first);
2209     Results.push_back(Tmp.second);
2210   } else {
2211     SDValue Tmp = ExpandLibCall(LC, Node, false);
2212     Results.push_back(Tmp);
2213   }
2214 }
2215 
2216 /// Issue libcalls to __{u}divmod to compute div / rem pairs.
2217 void
2218 SelectionDAGLegalize::ExpandDivRemLibCall(SDNode *Node,
2219                                           SmallVectorImpl<SDValue> &Results) {
2220   unsigned Opcode = Node->getOpcode();
2221   bool isSigned = Opcode == ISD::SDIVREM;
2222 
2223   RTLIB::Libcall LC;
2224   switch (Node->getSimpleValueType(0).SimpleTy) {
2225   default: llvm_unreachable("Unexpected request for libcall!");
2226   case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
2227   case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
2228   case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
2229   case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
2230   case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
2231   }
2232 
2233   // The input chain to this libcall is the entry node of the function.
2234   // Legalizing the call will automatically add the previous call to the
2235   // dependence.
2236   SDValue InChain = DAG.getEntryNode();
2237 
2238   EVT RetVT = Node->getValueType(0);
2239   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2240 
2241   TargetLowering::ArgListTy Args;
2242   TargetLowering::ArgListEntry Entry;
2243   for (const SDValue &Op : Node->op_values()) {
2244     EVT ArgVT = Op.getValueType();
2245     Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext());
2246     Entry.Node = Op;
2247     Entry.Ty = ArgTy;
2248     Entry.IsSExt = isSigned;
2249     Entry.IsZExt = !isSigned;
2250     Args.push_back(Entry);
2251   }
2252 
2253   // Also pass the return address of the remainder.
2254   SDValue FIPtr = DAG.CreateStackTemporary(RetVT);
2255   Entry.Node = FIPtr;
2256   Entry.Ty = RetTy->getPointerTo();
2257   Entry.IsSExt = isSigned;
2258   Entry.IsZExt = !isSigned;
2259   Args.push_back(Entry);
2260 
2261   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2262                                          TLI.getPointerTy(DAG.getDataLayout()));
2263 
2264   SDLoc dl(Node);
2265   TargetLowering::CallLoweringInfo CLI(DAG);
2266   CLI.setDebugLoc(dl)
2267       .setChain(InChain)
2268       .setLibCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee,
2269                     std::move(Args))
2270       .setSExtResult(isSigned)
2271       .setZExtResult(!isSigned);
2272 
2273   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2274 
2275   // Remainder is loaded back from the stack frame.
2276   SDValue Rem =
2277       DAG.getLoad(RetVT, dl, CallInfo.second, FIPtr, MachinePointerInfo());
2278   Results.push_back(CallInfo.first);
2279   Results.push_back(Rem);
2280 }
2281 
2282 /// Return true if sincos libcall is available.
2283 static bool isSinCosLibcallAvailable(SDNode *Node, const TargetLowering &TLI) {
2284   RTLIB::Libcall LC;
2285   switch (Node->getSimpleValueType(0).SimpleTy) {
2286   default: llvm_unreachable("Unexpected request for libcall!");
2287   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2288   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2289   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2290   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2291   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2292   }
2293   return TLI.getLibcallName(LC) != nullptr;
2294 }
2295 
2296 /// Only issue sincos libcall if both sin and cos are needed.
2297 static bool useSinCos(SDNode *Node) {
2298   unsigned OtherOpcode = Node->getOpcode() == ISD::FSIN
2299     ? ISD::FCOS : ISD::FSIN;
2300 
2301   SDValue Op0 = Node->getOperand(0);
2302   for (SDNode::use_iterator UI = Op0.getNode()->use_begin(),
2303        UE = Op0.getNode()->use_end(); UI != UE; ++UI) {
2304     SDNode *User = *UI;
2305     if (User == Node)
2306       continue;
2307     // The other user might have been turned into sincos already.
2308     if (User->getOpcode() == OtherOpcode || User->getOpcode() == ISD::FSINCOS)
2309       return true;
2310   }
2311   return false;
2312 }
2313 
2314 /// Issue libcalls to sincos to compute sin / cos pairs.
2315 void
2316 SelectionDAGLegalize::ExpandSinCosLibCall(SDNode *Node,
2317                                           SmallVectorImpl<SDValue> &Results) {
2318   RTLIB::Libcall LC;
2319   switch (Node->getSimpleValueType(0).SimpleTy) {
2320   default: llvm_unreachable("Unexpected request for libcall!");
2321   case MVT::f32:     LC = RTLIB::SINCOS_F32; break;
2322   case MVT::f64:     LC = RTLIB::SINCOS_F64; break;
2323   case MVT::f80:     LC = RTLIB::SINCOS_F80; break;
2324   case MVT::f128:    LC = RTLIB::SINCOS_F128; break;
2325   case MVT::ppcf128: LC = RTLIB::SINCOS_PPCF128; break;
2326   }
2327 
2328   // The input chain to this libcall is the entry node of the function.
2329   // Legalizing the call will automatically add the previous call to the
2330   // dependence.
2331   SDValue InChain = DAG.getEntryNode();
2332 
2333   EVT RetVT = Node->getValueType(0);
2334   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
2335 
2336   TargetLowering::ArgListTy Args;
2337   TargetLowering::ArgListEntry Entry;
2338 
2339   // Pass the argument.
2340   Entry.Node = Node->getOperand(0);
2341   Entry.Ty = RetTy;
2342   Entry.IsSExt = false;
2343   Entry.IsZExt = false;
2344   Args.push_back(Entry);
2345 
2346   // Pass the return address of sin.
2347   SDValue SinPtr = DAG.CreateStackTemporary(RetVT);
2348   Entry.Node = SinPtr;
2349   Entry.Ty = RetTy->getPointerTo();
2350   Entry.IsSExt = false;
2351   Entry.IsZExt = false;
2352   Args.push_back(Entry);
2353 
2354   // Also pass the return address of the cos.
2355   SDValue CosPtr = DAG.CreateStackTemporary(RetVT);
2356   Entry.Node = CosPtr;
2357   Entry.Ty = RetTy->getPointerTo();
2358   Entry.IsSExt = false;
2359   Entry.IsZExt = false;
2360   Args.push_back(Entry);
2361 
2362   SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
2363                                          TLI.getPointerTy(DAG.getDataLayout()));
2364 
2365   SDLoc dl(Node);
2366   TargetLowering::CallLoweringInfo CLI(DAG);
2367   CLI.setDebugLoc(dl).setChain(InChain).setLibCallee(
2368       TLI.getLibcallCallingConv(LC), Type::getVoidTy(*DAG.getContext()), Callee,
2369       std::move(Args));
2370 
2371   std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI);
2372 
2373   Results.push_back(
2374       DAG.getLoad(RetVT, dl, CallInfo.second, SinPtr, MachinePointerInfo()));
2375   Results.push_back(
2376       DAG.getLoad(RetVT, dl, CallInfo.second, CosPtr, MachinePointerInfo()));
2377 }
2378 
2379 /// This function is responsible for legalizing a
2380 /// INT_TO_FP operation of the specified operand when the target requests that
2381 /// we expand it.  At this point, we know that the result and operand types are
2382 /// legal for the target.
2383 SDValue SelectionDAGLegalize::ExpandLegalINT_TO_FP(SDNode *Node,
2384                                                    SDValue &Chain) {
2385   bool isSigned = (Node->getOpcode() == ISD::STRICT_SINT_TO_FP ||
2386                    Node->getOpcode() == ISD::SINT_TO_FP);
2387   EVT DestVT = Node->getValueType(0);
2388   SDLoc dl(Node);
2389   unsigned OpNo = Node->isStrictFPOpcode() ? 1 : 0;
2390   SDValue Op0 = Node->getOperand(OpNo);
2391   EVT SrcVT = Op0.getValueType();
2392 
2393   // TODO: Should any fast-math-flags be set for the created nodes?
2394   LLVM_DEBUG(dbgs() << "Legalizing INT_TO_FP\n");
2395   if (SrcVT == MVT::i32 && TLI.isTypeLegal(MVT::f64)) {
2396     LLVM_DEBUG(dbgs() << "32-bit [signed|unsigned] integer to float/double "
2397                          "expansion\n");
2398 
2399     // Get the stack frame index of a 8 byte buffer.
2400     SDValue StackSlot = DAG.CreateStackTemporary(MVT::f64);
2401 
2402     SDValue Lo = Op0;
2403     // if signed map to unsigned space
2404     if (isSigned) {
2405       // Invert sign bit (signed to unsigned mapping).
2406       Lo = DAG.getNode(ISD::XOR, dl, MVT::i32, Lo,
2407                        DAG.getConstant(0x80000000u, dl, MVT::i32));
2408     }
2409     // Initial hi portion of constructed double.
2410     SDValue Hi = DAG.getConstant(0x43300000u, dl, MVT::i32);
2411 
2412     // If this a big endian target, swap the lo and high data.
2413     if (DAG.getDataLayout().isBigEndian())
2414       std::swap(Lo, Hi);
2415 
2416     SDValue MemChain = DAG.getEntryNode();
2417 
2418     // Store the lo of the constructed double.
2419     SDValue Store1 = DAG.getStore(MemChain, dl, Lo, StackSlot,
2420                                   MachinePointerInfo());
2421     // Store the hi of the constructed double.
2422     SDValue HiPtr = DAG.getMemBasePlusOffset(StackSlot, TypeSize::Fixed(4), dl);
2423     SDValue Store2 =
2424         DAG.getStore(MemChain, dl, Hi, HiPtr, MachinePointerInfo());
2425     MemChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Store1, Store2);
2426 
2427     // load the constructed double
2428     SDValue Load =
2429         DAG.getLoad(MVT::f64, dl, MemChain, StackSlot, MachinePointerInfo());
2430     // FP constant to bias correct the final result
2431     SDValue Bias = DAG.getConstantFP(isSigned ?
2432                                      BitsToDouble(0x4330000080000000ULL) :
2433                                      BitsToDouble(0x4330000000000000ULL),
2434                                      dl, MVT::f64);
2435     // Subtract the bias and get the final result.
2436     SDValue Sub;
2437     SDValue Result;
2438     if (Node->isStrictFPOpcode()) {
2439       Sub = DAG.getNode(ISD::STRICT_FSUB, dl, {MVT::f64, MVT::Other},
2440                         {Node->getOperand(0), Load, Bias});
2441       Chain = Sub.getValue(1);
2442       if (DestVT != Sub.getValueType()) {
2443         std::pair<SDValue, SDValue> ResultPair;
2444         ResultPair =
2445             DAG.getStrictFPExtendOrRound(Sub, Chain, dl, DestVT);
2446         Result = ResultPair.first;
2447         Chain = ResultPair.second;
2448       }
2449       else
2450         Result = Sub;
2451     } else {
2452       Sub = DAG.getNode(ISD::FSUB, dl, MVT::f64, Load, Bias);
2453       Result = DAG.getFPExtendOrRound(Sub, dl, DestVT);
2454     }
2455     return Result;
2456   }
2457   // Code below here assumes !isSigned without checking again.
2458   assert(!isSigned && "Legalize cannot Expand SINT_TO_FP for i64 yet");
2459 
2460   // TODO: Generalize this for use with other types.
2461   if ((SrcVT == MVT::i32 || SrcVT == MVT::i64) && DestVT == MVT::f32) {
2462     LLVM_DEBUG(dbgs() << "Converting unsigned i32/i64 to f32\n");
2463     // For unsigned conversions, convert them to signed conversions using the
2464     // algorithm from the x86_64 __floatundisf in compiler_rt. That method
2465     // should be valid for i32->f32 as well.
2466 
2467     // TODO: This really should be implemented using a branch rather than a
2468     // select.  We happen to get lucky and machinesink does the right
2469     // thing most of the time.  This would be a good candidate for a
2470     // pseudo-op, or, even better, for whole-function isel.
2471     EVT SetCCVT = getSetCCResultType(SrcVT);
2472 
2473     SDValue SignBitTest = DAG.getSetCC(
2474         dl, SetCCVT, Op0, DAG.getConstant(0, dl, SrcVT), ISD::SETLT);
2475 
2476     EVT ShiftVT = TLI.getShiftAmountTy(SrcVT, DAG.getDataLayout());
2477     SDValue ShiftConst = DAG.getConstant(1, dl, ShiftVT);
2478     SDValue Shr = DAG.getNode(ISD::SRL, dl, SrcVT, Op0, ShiftConst);
2479     SDValue AndConst = DAG.getConstant(1, dl, SrcVT);
2480     SDValue And = DAG.getNode(ISD::AND, dl, SrcVT, Op0, AndConst);
2481     SDValue Or = DAG.getNode(ISD::OR, dl, SrcVT, And, Shr);
2482 
2483     SDValue Slow, Fast;
2484     if (Node->isStrictFPOpcode()) {
2485       // In strict mode, we must avoid spurious exceptions, and therefore
2486       // must make sure to only emit a single STRICT_SINT_TO_FP.
2487       SDValue InCvt = DAG.getSelect(dl, SrcVT, SignBitTest, Or, Op0);
2488       Fast = DAG.getNode(ISD::STRICT_SINT_TO_FP, dl, { DestVT, MVT::Other },
2489                          { Node->getOperand(0), InCvt });
2490       Slow = DAG.getNode(ISD::STRICT_FADD, dl, { DestVT, MVT::Other },
2491                          { Fast.getValue(1), Fast, Fast });
2492       Chain = Slow.getValue(1);
2493       // The STRICT_SINT_TO_FP inherits the exception mode from the
2494       // incoming STRICT_UINT_TO_FP node; the STRICT_FADD node can
2495       // never raise any exception.
2496       SDNodeFlags Flags;
2497       Flags.setNoFPExcept(Node->getFlags().hasNoFPExcept());
2498       Fast->setFlags(Flags);
2499       Flags.setNoFPExcept(true);
2500       Slow->setFlags(Flags);
2501     } else {
2502       SDValue SignCvt = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Or);
2503       Slow = DAG.getNode(ISD::FADD, dl, DestVT, SignCvt, SignCvt);
2504       Fast = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2505     }
2506 
2507     return DAG.getSelect(dl, DestVT, SignBitTest, Slow, Fast);
2508   }
2509 
2510   // The following optimization is valid only if every value in SrcVT (when
2511   // treated as signed) is representable in DestVT.  Check that the mantissa
2512   // size of DestVT is >= than the number of bits in SrcVT -1.
2513   assert(APFloat::semanticsPrecision(DAG.EVTToAPFloatSemantics(DestVT)) >=
2514              SrcVT.getSizeInBits() - 1 &&
2515          "Cannot perform lossless SINT_TO_FP!");
2516 
2517   SDValue Tmp1;
2518   if (Node->isStrictFPOpcode()) {
2519     Tmp1 = DAG.getNode(ISD::STRICT_SINT_TO_FP, dl, { DestVT, MVT::Other },
2520                        { Node->getOperand(0), Op0 });
2521   } else
2522     Tmp1 = DAG.getNode(ISD::SINT_TO_FP, dl, DestVT, Op0);
2523 
2524   SDValue SignSet = DAG.getSetCC(dl, getSetCCResultType(SrcVT), Op0,
2525                                  DAG.getConstant(0, dl, SrcVT), ISD::SETLT);
2526   SDValue Zero = DAG.getIntPtrConstant(0, dl),
2527           Four = DAG.getIntPtrConstant(4, dl);
2528   SDValue CstOffset = DAG.getSelect(dl, Zero.getValueType(),
2529                                     SignSet, Four, Zero);
2530 
2531   // If the sign bit of the integer is set, the large number will be treated
2532   // as a negative number.  To counteract this, the dynamic code adds an
2533   // offset depending on the data type.
2534   uint64_t FF;
2535   switch (SrcVT.getSimpleVT().SimpleTy) {
2536   default: llvm_unreachable("Unsupported integer type!");
2537   case MVT::i8 : FF = 0x43800000ULL; break;  // 2^8  (as a float)
2538   case MVT::i16: FF = 0x47800000ULL; break;  // 2^16 (as a float)
2539   case MVT::i32: FF = 0x4F800000ULL; break;  // 2^32 (as a float)
2540   case MVT::i64: FF = 0x5F800000ULL; break;  // 2^64 (as a float)
2541   }
2542   if (DAG.getDataLayout().isLittleEndian())
2543     FF <<= 32;
2544   Constant *FudgeFactor = ConstantInt::get(
2545                                        Type::getInt64Ty(*DAG.getContext()), FF);
2546 
2547   SDValue CPIdx =
2548       DAG.getConstantPool(FudgeFactor, TLI.getPointerTy(DAG.getDataLayout()));
2549   Align Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlign();
2550   CPIdx = DAG.getNode(ISD::ADD, dl, CPIdx.getValueType(), CPIdx, CstOffset);
2551   Alignment = commonAlignment(Alignment, 4);
2552   SDValue FudgeInReg;
2553   if (DestVT == MVT::f32)
2554     FudgeInReg = DAG.getLoad(
2555         MVT::f32, dl, DAG.getEntryNode(), CPIdx,
2556         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
2557         Alignment);
2558   else {
2559     SDValue Load = DAG.getExtLoad(
2560         ISD::EXTLOAD, dl, DestVT, DAG.getEntryNode(), CPIdx,
2561         MachinePointerInfo::getConstantPool(DAG.getMachineFunction()), MVT::f32,
2562         Alignment);
2563     HandleSDNode Handle(Load);
2564     LegalizeOp(Load.getNode());
2565     FudgeInReg = Handle.getValue();
2566   }
2567 
2568   if (Node->isStrictFPOpcode()) {
2569     SDValue Result = DAG.getNode(ISD::STRICT_FADD, dl, { DestVT, MVT::Other },
2570                                  { Tmp1.getValue(1), Tmp1, FudgeInReg });
2571     Chain = Result.getValue(1);
2572     return Result;
2573   }
2574 
2575   return DAG.getNode(ISD::FADD, dl, DestVT, Tmp1, FudgeInReg);
2576 }
2577 
2578 /// This function is responsible for legalizing a
2579 /// *INT_TO_FP operation of the specified operand when the target requests that
2580 /// we promote it.  At this point, we know that the result and operand types are
2581 /// legal for the target, and that there is a legal UINT_TO_FP or SINT_TO_FP
2582 /// operation that takes a larger input.
2583 void SelectionDAGLegalize::PromoteLegalINT_TO_FP(
2584     SDNode *N, const SDLoc &dl, SmallVectorImpl<SDValue> &Results) {
2585   bool IsStrict = N->isStrictFPOpcode();
2586   bool IsSigned = N->getOpcode() == ISD::SINT_TO_FP ||
2587                   N->getOpcode() == ISD::STRICT_SINT_TO_FP;
2588   EVT DestVT = N->getValueType(0);
2589   SDValue LegalOp = N->getOperand(IsStrict ? 1 : 0);
2590   unsigned UIntOp = IsStrict ? ISD::STRICT_UINT_TO_FP : ISD::UINT_TO_FP;
2591   unsigned SIntOp = IsStrict ? ISD::STRICT_SINT_TO_FP : ISD::SINT_TO_FP;
2592 
2593   // First step, figure out the appropriate *INT_TO_FP operation to use.
2594   EVT NewInTy = LegalOp.getValueType();
2595 
2596   unsigned OpToUse = 0;
2597 
2598   // Scan for the appropriate larger type to use.
2599   while (true) {
2600     NewInTy = (MVT::SimpleValueType)(NewInTy.getSimpleVT().SimpleTy+1);
2601     assert(NewInTy.isInteger() && "Ran out of possibilities!");
2602 
2603     // If the target supports SINT_TO_FP of this type, use it.
2604     if (TLI.isOperationLegalOrCustom(SIntOp, NewInTy)) {
2605       OpToUse = SIntOp;
2606       break;
2607     }
2608     if (IsSigned)
2609       continue;
2610 
2611     // If the target supports UINT_TO_FP of this type, use it.
2612     if (TLI.isOperationLegalOrCustom(UIntOp, NewInTy)) {
2613       OpToUse = UIntOp;
2614       break;
2615     }
2616 
2617     // Otherwise, try a larger type.
2618   }
2619 
2620   // Okay, we found the operation and type to use.  Zero extend our input to the
2621   // desired type then run the operation on it.
2622   if (IsStrict) {
2623     SDValue Res =
2624         DAG.getNode(OpToUse, dl, {DestVT, MVT::Other},
2625                     {N->getOperand(0),
2626                      DAG.getNode(IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2627                                  dl, NewInTy, LegalOp)});
2628     Results.push_back(Res);
2629     Results.push_back(Res.getValue(1));
2630     return;
2631   }
2632 
2633   Results.push_back(
2634       DAG.getNode(OpToUse, dl, DestVT,
2635                   DAG.getNode(IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
2636                               dl, NewInTy, LegalOp)));
2637 }
2638 
2639 /// This function is responsible for legalizing a
2640 /// FP_TO_*INT operation of the specified operand when the target requests that
2641 /// we promote it.  At this point, we know that the result and operand types are
2642 /// legal for the target, and that there is a legal FP_TO_UINT or FP_TO_SINT
2643 /// operation that returns a larger result.
2644 void SelectionDAGLegalize::PromoteLegalFP_TO_INT(SDNode *N, const SDLoc &dl,
2645                                                  SmallVectorImpl<SDValue> &Results) {
2646   bool IsStrict = N->isStrictFPOpcode();
2647   bool IsSigned = N->getOpcode() == ISD::FP_TO_SINT ||
2648                   N->getOpcode() == ISD::STRICT_FP_TO_SINT;
2649   EVT DestVT = N->getValueType(0);
2650   SDValue LegalOp = N->getOperand(IsStrict ? 1 : 0);
2651   // First step, figure out the appropriate FP_TO*INT operation to use.
2652   EVT NewOutTy = DestVT;
2653 
2654   unsigned OpToUse = 0;
2655 
2656   // Scan for the appropriate larger type to use.
2657   while (true) {
2658     NewOutTy = (MVT::SimpleValueType)(NewOutTy.getSimpleVT().SimpleTy+1);
2659     assert(NewOutTy.isInteger() && "Ran out of possibilities!");
2660 
2661     // A larger signed type can hold all unsigned values of the requested type,
2662     // so using FP_TO_SINT is valid
2663     OpToUse = IsStrict ? ISD::STRICT_FP_TO_SINT : ISD::FP_TO_SINT;
2664     if (TLI.isOperationLegalOrCustom(OpToUse, NewOutTy))
2665       break;
2666 
2667     // However, if the value may be < 0.0, we *must* use some FP_TO_SINT.
2668     OpToUse = IsStrict ? ISD::STRICT_FP_TO_UINT : ISD::FP_TO_UINT;
2669     if (!IsSigned && TLI.isOperationLegalOrCustom(OpToUse, NewOutTy))
2670       break;
2671 
2672     // Otherwise, try a larger type.
2673   }
2674 
2675   // Okay, we found the operation and type to use.
2676   SDValue Operation;
2677   if (IsStrict) {
2678     SDVTList VTs = DAG.getVTList(NewOutTy, MVT::Other);
2679     Operation = DAG.getNode(OpToUse, dl, VTs, N->getOperand(0), LegalOp);
2680   } else
2681     Operation = DAG.getNode(OpToUse, dl, NewOutTy, LegalOp);
2682 
2683   // Truncate the result of the extended FP_TO_*INT operation to the desired
2684   // size.
2685   SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, DestVT, Operation);
2686   Results.push_back(Trunc);
2687   if (IsStrict)
2688     Results.push_back(Operation.getValue(1));
2689 }
2690 
2691 /// Legalize a BITREVERSE scalar/vector operation as a series of mask + shifts.
2692 SDValue SelectionDAGLegalize::ExpandBITREVERSE(SDValue Op, const SDLoc &dl) {
2693   EVT VT = Op.getValueType();
2694   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2695   unsigned Sz = VT.getScalarSizeInBits();
2696 
2697   SDValue Tmp, Tmp2, Tmp3;
2698 
2699   // If we can, perform BSWAP first and then the mask+swap the i4, then i2
2700   // and finally the i1 pairs.
2701   // TODO: We can easily support i4/i2 legal types if any target ever does.
2702   if (Sz >= 8 && isPowerOf2_32(Sz)) {
2703     // Create the masks - repeating the pattern every byte.
2704     APInt MaskHi4 = APInt::getSplat(Sz, APInt(8, 0xF0));
2705     APInt MaskHi2 = APInt::getSplat(Sz, APInt(8, 0xCC));
2706     APInt MaskHi1 = APInt::getSplat(Sz, APInt(8, 0xAA));
2707     APInt MaskLo4 = APInt::getSplat(Sz, APInt(8, 0x0F));
2708     APInt MaskLo2 = APInt::getSplat(Sz, APInt(8, 0x33));
2709     APInt MaskLo1 = APInt::getSplat(Sz, APInt(8, 0x55));
2710 
2711     // BSWAP if the type is wider than a single byte.
2712     Tmp = (Sz > 8 ? DAG.getNode(ISD::BSWAP, dl, VT, Op) : Op);
2713 
2714     // swap i4: ((V & 0xF0) >> 4) | ((V & 0x0F) << 4)
2715     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi4, dl, VT));
2716     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo4, dl, VT));
2717     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(4, dl, SHVT));
2718     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(4, dl, SHVT));
2719     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2720 
2721     // swap i2: ((V & 0xCC) >> 2) | ((V & 0x33) << 2)
2722     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi2, dl, VT));
2723     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo2, dl, VT));
2724     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(2, dl, SHVT));
2725     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(2, dl, SHVT));
2726     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2727 
2728     // swap i1: ((V & 0xAA) >> 1) | ((V & 0x55) << 1)
2729     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskHi1, dl, VT));
2730     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp, DAG.getConstant(MaskLo1, dl, VT));
2731     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Tmp2, DAG.getConstant(1, dl, SHVT));
2732     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Tmp3, DAG.getConstant(1, dl, SHVT));
2733     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp3);
2734     return Tmp;
2735   }
2736 
2737   Tmp = DAG.getConstant(0, dl, VT);
2738   for (unsigned I = 0, J = Sz-1; I < Sz; ++I, --J) {
2739     if (I < J)
2740       Tmp2 =
2741           DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(J - I, dl, SHVT));
2742     else
2743       Tmp2 =
2744           DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(I - J, dl, SHVT));
2745 
2746     APInt Shift(Sz, 1);
2747     Shift <<= J;
2748     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(Shift, dl, VT));
2749     Tmp = DAG.getNode(ISD::OR, dl, VT, Tmp, Tmp2);
2750   }
2751 
2752   return Tmp;
2753 }
2754 
2755 /// Open code the operations for BSWAP of the specified operation.
2756 SDValue SelectionDAGLegalize::ExpandBSWAP(SDValue Op, const SDLoc &dl) {
2757   EVT VT = Op.getValueType();
2758   EVT SHVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2759   SDValue Tmp1, Tmp2, Tmp3, Tmp4, Tmp5, Tmp6, Tmp7, Tmp8;
2760   switch (VT.getSimpleVT().getScalarType().SimpleTy) {
2761   default: llvm_unreachable("Unhandled Expand type in BSWAP!");
2762   case MVT::i16:
2763     // Use a rotate by 8. This can be further expanded if necessary.
2764     return DAG.getNode(ISD::ROTL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2765   case MVT::i32:
2766     Tmp4 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2767     Tmp3 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2768     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2769     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2770     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2771                        DAG.getConstant(0xFF0000, dl, VT));
2772     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2, DAG.getConstant(0xFF00, dl, VT));
2773     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2774     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2775     return DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2776   case MVT::i64:
2777     Tmp8 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2778     Tmp7 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2779     Tmp6 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2780     Tmp5 = DAG.getNode(ISD::SHL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2781     Tmp4 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(8, dl, SHVT));
2782     Tmp3 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(24, dl, SHVT));
2783     Tmp2 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(40, dl, SHVT));
2784     Tmp1 = DAG.getNode(ISD::SRL, dl, VT, Op, DAG.getConstant(56, dl, SHVT));
2785     Tmp7 = DAG.getNode(ISD::AND, dl, VT, Tmp7,
2786                        DAG.getConstant(255ULL<<48, dl, VT));
2787     Tmp6 = DAG.getNode(ISD::AND, dl, VT, Tmp6,
2788                        DAG.getConstant(255ULL<<40, dl, VT));
2789     Tmp5 = DAG.getNode(ISD::AND, dl, VT, Tmp5,
2790                        DAG.getConstant(255ULL<<32, dl, VT));
2791     Tmp4 = DAG.getNode(ISD::AND, dl, VT, Tmp4,
2792                        DAG.getConstant(255ULL<<24, dl, VT));
2793     Tmp3 = DAG.getNode(ISD::AND, dl, VT, Tmp3,
2794                        DAG.getConstant(255ULL<<16, dl, VT));
2795     Tmp2 = DAG.getNode(ISD::AND, dl, VT, Tmp2,
2796                        DAG.getConstant(255ULL<<8 , dl, VT));
2797     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp7);
2798     Tmp6 = DAG.getNode(ISD::OR, dl, VT, Tmp6, Tmp5);
2799     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp3);
2800     Tmp2 = DAG.getNode(ISD::OR, dl, VT, Tmp2, Tmp1);
2801     Tmp8 = DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp6);
2802     Tmp4 = DAG.getNode(ISD::OR, dl, VT, Tmp4, Tmp2);
2803     return DAG.getNode(ISD::OR, dl, VT, Tmp8, Tmp4);
2804   }
2805 }
2806 
2807 /// Open code the operations for PARITY of the specified operation.
2808 SDValue SelectionDAGLegalize::ExpandPARITY(SDValue Op, const SDLoc &dl) {
2809   EVT VT = Op.getValueType();
2810   EVT ShVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
2811   unsigned Sz = VT.getScalarSizeInBits();
2812 
2813   // If CTPOP is legal, use it. Otherwise use shifts and xor.
2814   SDValue Result;
2815   if (TLI.isOperationLegal(ISD::CTPOP, VT)) {
2816     Result = DAG.getNode(ISD::CTPOP, dl, VT, Op);
2817   } else {
2818     Result = Op;
2819     for (unsigned i = Log2_32_Ceil(Sz); i != 0;) {
2820       SDValue Shift = DAG.getNode(ISD::SRL, dl, VT, Result,
2821                                   DAG.getConstant(1ULL << (--i), dl, ShVT));
2822       Result = DAG.getNode(ISD::XOR, dl, VT, Result, Shift);
2823     }
2824   }
2825 
2826   return DAG.getNode(ISD::AND, dl, VT, Result, DAG.getConstant(1, dl, VT));
2827 }
2828 
2829 bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
2830   LLVM_DEBUG(dbgs() << "Trying to expand node\n");
2831   SmallVector<SDValue, 8> Results;
2832   SDLoc dl(Node);
2833   SDValue Tmp1, Tmp2, Tmp3, Tmp4;
2834   bool NeedInvert;
2835   switch (Node->getOpcode()) {
2836   case ISD::ABS:
2837     if (TLI.expandABS(Node, Tmp1, DAG))
2838       Results.push_back(Tmp1);
2839     break;
2840   case ISD::CTPOP:
2841     if (TLI.expandCTPOP(Node, Tmp1, DAG))
2842       Results.push_back(Tmp1);
2843     break;
2844   case ISD::CTLZ:
2845   case ISD::CTLZ_ZERO_UNDEF:
2846     if (TLI.expandCTLZ(Node, Tmp1, DAG))
2847       Results.push_back(Tmp1);
2848     break;
2849   case ISD::CTTZ:
2850   case ISD::CTTZ_ZERO_UNDEF:
2851     if (TLI.expandCTTZ(Node, Tmp1, DAG))
2852       Results.push_back(Tmp1);
2853     break;
2854   case ISD::BITREVERSE:
2855     Results.push_back(ExpandBITREVERSE(Node->getOperand(0), dl));
2856     break;
2857   case ISD::BSWAP:
2858     Results.push_back(ExpandBSWAP(Node->getOperand(0), dl));
2859     break;
2860   case ISD::PARITY:
2861     Results.push_back(ExpandPARITY(Node->getOperand(0), dl));
2862     break;
2863   case ISD::FRAMEADDR:
2864   case ISD::RETURNADDR:
2865   case ISD::FRAME_TO_ARGS_OFFSET:
2866     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
2867     break;
2868   case ISD::EH_DWARF_CFA: {
2869     SDValue CfaArg = DAG.getSExtOrTrunc(Node->getOperand(0), dl,
2870                                         TLI.getPointerTy(DAG.getDataLayout()));
2871     SDValue Offset = DAG.getNode(ISD::ADD, dl,
2872                                  CfaArg.getValueType(),
2873                                  DAG.getNode(ISD::FRAME_TO_ARGS_OFFSET, dl,
2874                                              CfaArg.getValueType()),
2875                                  CfaArg);
2876     SDValue FA = DAG.getNode(
2877         ISD::FRAMEADDR, dl, TLI.getPointerTy(DAG.getDataLayout()),
2878         DAG.getConstant(0, dl, TLI.getPointerTy(DAG.getDataLayout())));
2879     Results.push_back(DAG.getNode(ISD::ADD, dl, FA.getValueType(),
2880                                   FA, Offset));
2881     break;
2882   }
2883   case ISD::FLT_ROUNDS_:
2884     Results.push_back(DAG.getConstant(1, dl, Node->getValueType(0)));
2885     Results.push_back(Node->getOperand(0));
2886     break;
2887   case ISD::EH_RETURN:
2888   case ISD::EH_LABEL:
2889   case ISD::PREFETCH:
2890   case ISD::VAEND:
2891   case ISD::EH_SJLJ_LONGJMP:
2892     // If the target didn't expand these, there's nothing to do, so just
2893     // preserve the chain and be done.
2894     Results.push_back(Node->getOperand(0));
2895     break;
2896   case ISD::READCYCLECOUNTER:
2897     // If the target didn't expand this, just return 'zero' and preserve the
2898     // chain.
2899     Results.append(Node->getNumValues() - 1,
2900                    DAG.getConstant(0, dl, Node->getValueType(0)));
2901     Results.push_back(Node->getOperand(0));
2902     break;
2903   case ISD::EH_SJLJ_SETJMP:
2904     // If the target didn't expand this, just return 'zero' and preserve the
2905     // chain.
2906     Results.push_back(DAG.getConstant(0, dl, MVT::i32));
2907     Results.push_back(Node->getOperand(0));
2908     break;
2909   case ISD::ATOMIC_LOAD: {
2910     // There is no libcall for atomic load; fake it with ATOMIC_CMP_SWAP.
2911     SDValue Zero = DAG.getConstant(0, dl, Node->getValueType(0));
2912     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2913     SDValue Swap = DAG.getAtomicCmpSwap(
2914         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2915         Node->getOperand(0), Node->getOperand(1), Zero, Zero,
2916         cast<AtomicSDNode>(Node)->getMemOperand());
2917     Results.push_back(Swap.getValue(0));
2918     Results.push_back(Swap.getValue(1));
2919     break;
2920   }
2921   case ISD::ATOMIC_STORE: {
2922     // There is no libcall for atomic store; fake it with ATOMIC_SWAP.
2923     SDValue Swap = DAG.getAtomic(ISD::ATOMIC_SWAP, dl,
2924                                  cast<AtomicSDNode>(Node)->getMemoryVT(),
2925                                  Node->getOperand(0),
2926                                  Node->getOperand(1), Node->getOperand(2),
2927                                  cast<AtomicSDNode>(Node)->getMemOperand());
2928     Results.push_back(Swap.getValue(1));
2929     break;
2930   }
2931   case ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS: {
2932     // Expanding an ATOMIC_CMP_SWAP_WITH_SUCCESS produces an ATOMIC_CMP_SWAP and
2933     // splits out the success value as a comparison. Expanding the resulting
2934     // ATOMIC_CMP_SWAP will produce a libcall.
2935     SDVTList VTs = DAG.getVTList(Node->getValueType(0), MVT::Other);
2936     SDValue Res = DAG.getAtomicCmpSwap(
2937         ISD::ATOMIC_CMP_SWAP, dl, cast<AtomicSDNode>(Node)->getMemoryVT(), VTs,
2938         Node->getOperand(0), Node->getOperand(1), Node->getOperand(2),
2939         Node->getOperand(3), cast<MemSDNode>(Node)->getMemOperand());
2940 
2941     SDValue ExtRes = Res;
2942     SDValue LHS = Res;
2943     SDValue RHS = Node->getOperand(1);
2944 
2945     EVT AtomicType = cast<AtomicSDNode>(Node)->getMemoryVT();
2946     EVT OuterType = Node->getValueType(0);
2947     switch (TLI.getExtendForAtomicOps()) {
2948     case ISD::SIGN_EXTEND:
2949       LHS = DAG.getNode(ISD::AssertSext, dl, OuterType, Res,
2950                         DAG.getValueType(AtomicType));
2951       RHS = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, OuterType,
2952                         Node->getOperand(2), DAG.getValueType(AtomicType));
2953       ExtRes = LHS;
2954       break;
2955     case ISD::ZERO_EXTEND:
2956       LHS = DAG.getNode(ISD::AssertZext, dl, OuterType, Res,
2957                         DAG.getValueType(AtomicType));
2958       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2959       ExtRes = LHS;
2960       break;
2961     case ISD::ANY_EXTEND:
2962       LHS = DAG.getZeroExtendInReg(Res, dl, AtomicType);
2963       RHS = DAG.getZeroExtendInReg(Node->getOperand(2), dl, AtomicType);
2964       break;
2965     default:
2966       llvm_unreachable("Invalid atomic op extension");
2967     }
2968 
2969     SDValue Success =
2970         DAG.getSetCC(dl, Node->getValueType(1), LHS, RHS, ISD::SETEQ);
2971 
2972     Results.push_back(ExtRes.getValue(0));
2973     Results.push_back(Success);
2974     Results.push_back(Res.getValue(1));
2975     break;
2976   }
2977   case ISD::DYNAMIC_STACKALLOC:
2978     ExpandDYNAMIC_STACKALLOC(Node, Results);
2979     break;
2980   case ISD::MERGE_VALUES:
2981     for (unsigned i = 0; i < Node->getNumValues(); i++)
2982       Results.push_back(Node->getOperand(i));
2983     break;
2984   case ISD::UNDEF: {
2985     EVT VT = Node->getValueType(0);
2986     if (VT.isInteger())
2987       Results.push_back(DAG.getConstant(0, dl, VT));
2988     else {
2989       assert(VT.isFloatingPoint() && "Unknown value type!");
2990       Results.push_back(DAG.getConstantFP(0, dl, VT));
2991     }
2992     break;
2993   }
2994   case ISD::STRICT_FP_ROUND:
2995     // When strict mode is enforced we can't do expansion because it
2996     // does not honor the "strict" properties. Only libcall is allowed.
2997     if (TLI.isStrictFPEnabled())
2998       break;
2999     // We might as well mutate to FP_ROUND when FP_ROUND operation is legal
3000     // since this operation is more efficient than stack operation.
3001     if (TLI.getStrictFPOperationAction(Node->getOpcode(),
3002                                        Node->getValueType(0))
3003         == TargetLowering::Legal)
3004       break;
3005     // We fall back to use stack operation when the FP_ROUND operation
3006     // isn't available.
3007     Tmp1 = EmitStackConvert(Node->getOperand(1),
3008                             Node->getValueType(0),
3009                             Node->getValueType(0), dl, Node->getOperand(0));
3010     ReplaceNode(Node, Tmp1.getNode());
3011     LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_ROUND node\n");
3012     return true;
3013   case ISD::FP_ROUND:
3014   case ISD::BITCAST:
3015     Tmp1 = EmitStackConvert(Node->getOperand(0),
3016                             Node->getValueType(0),
3017                             Node->getValueType(0), dl);
3018     Results.push_back(Tmp1);
3019     break;
3020   case ISD::STRICT_FP_EXTEND:
3021     // When strict mode is enforced we can't do expansion because it
3022     // does not honor the "strict" properties. Only libcall is allowed.
3023     if (TLI.isStrictFPEnabled())
3024       break;
3025     // We might as well mutate to FP_EXTEND when FP_EXTEND operation is legal
3026     // since this operation is more efficient than stack operation.
3027     if (TLI.getStrictFPOperationAction(Node->getOpcode(),
3028                                        Node->getValueType(0))
3029         == TargetLowering::Legal)
3030       break;
3031     // We fall back to use stack operation when the FP_EXTEND operation
3032     // isn't available.
3033     Tmp1 = EmitStackConvert(Node->getOperand(1),
3034                             Node->getOperand(1).getValueType(),
3035                             Node->getValueType(0), dl, Node->getOperand(0));
3036     ReplaceNode(Node, Tmp1.getNode());
3037     LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_EXTEND node\n");
3038     return true;
3039   case ISD::FP_EXTEND:
3040     Tmp1 = EmitStackConvert(Node->getOperand(0),
3041                             Node->getOperand(0).getValueType(),
3042                             Node->getValueType(0), dl);
3043     Results.push_back(Tmp1);
3044     break;
3045   case ISD::SIGN_EXTEND_INREG: {
3046     EVT ExtraVT = cast<VTSDNode>(Node->getOperand(1))->getVT();
3047     EVT VT = Node->getValueType(0);
3048 
3049     // An in-register sign-extend of a boolean is a negation:
3050     // 'true' (1) sign-extended is -1.
3051     // 'false' (0) sign-extended is 0.
3052     // However, we must mask the high bits of the source operand because the
3053     // SIGN_EXTEND_INREG does not guarantee that the high bits are already zero.
3054 
3055     // TODO: Do this for vectors too?
3056     if (ExtraVT.getSizeInBits() == 1) {
3057       SDValue One = DAG.getConstant(1, dl, VT);
3058       SDValue And = DAG.getNode(ISD::AND, dl, VT, Node->getOperand(0), One);
3059       SDValue Zero = DAG.getConstant(0, dl, VT);
3060       SDValue Neg = DAG.getNode(ISD::SUB, dl, VT, Zero, And);
3061       Results.push_back(Neg);
3062       break;
3063     }
3064 
3065     // NOTE: we could fall back on load/store here too for targets without
3066     // SRA.  However, it is doubtful that any exist.
3067     EVT ShiftAmountTy = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
3068     unsigned BitsDiff = VT.getScalarSizeInBits() -
3069                         ExtraVT.getScalarSizeInBits();
3070     SDValue ShiftCst = DAG.getConstant(BitsDiff, dl, ShiftAmountTy);
3071     Tmp1 = DAG.getNode(ISD::SHL, dl, Node->getValueType(0),
3072                        Node->getOperand(0), ShiftCst);
3073     Tmp1 = DAG.getNode(ISD::SRA, dl, Node->getValueType(0), Tmp1, ShiftCst);
3074     Results.push_back(Tmp1);
3075     break;
3076   }
3077   case ISD::UINT_TO_FP:
3078   case ISD::STRICT_UINT_TO_FP:
3079     if (TLI.expandUINT_TO_FP(Node, Tmp1, Tmp2, DAG)) {
3080       Results.push_back(Tmp1);
3081       if (Node->isStrictFPOpcode())
3082         Results.push_back(Tmp2);
3083       break;
3084     }
3085     LLVM_FALLTHROUGH;
3086   case ISD::SINT_TO_FP:
3087   case ISD::STRICT_SINT_TO_FP:
3088     Tmp1 = ExpandLegalINT_TO_FP(Node, Tmp2);
3089     Results.push_back(Tmp1);
3090     if (Node->isStrictFPOpcode())
3091       Results.push_back(Tmp2);
3092     break;
3093   case ISD::FP_TO_SINT:
3094     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG))
3095       Results.push_back(Tmp1);
3096     break;
3097   case ISD::STRICT_FP_TO_SINT:
3098     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG)) {
3099       ReplaceNode(Node, Tmp1.getNode());
3100       LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_TO_SINT node\n");
3101       return true;
3102     }
3103     break;
3104   case ISD::FP_TO_UINT:
3105     if (TLI.expandFP_TO_UINT(Node, Tmp1, Tmp2, DAG))
3106       Results.push_back(Tmp1);
3107     break;
3108   case ISD::STRICT_FP_TO_UINT:
3109     if (TLI.expandFP_TO_UINT(Node, Tmp1, Tmp2, DAG)) {
3110       // Relink the chain.
3111       DAG.ReplaceAllUsesOfValueWith(SDValue(Node,1), Tmp2);
3112       // Replace the new UINT result.
3113       ReplaceNodeWithValue(SDValue(Node, 0), Tmp1);
3114       LLVM_DEBUG(dbgs() << "Successfully expanded STRICT_FP_TO_UINT node\n");
3115       return true;
3116     }
3117     break;
3118   case ISD::VAARG:
3119     Results.push_back(DAG.expandVAArg(Node));
3120     Results.push_back(Results[0].getValue(1));
3121     break;
3122   case ISD::VACOPY:
3123     Results.push_back(DAG.expandVACopy(Node));
3124     break;
3125   case ISD::EXTRACT_VECTOR_ELT:
3126     if (Node->getOperand(0).getValueType().getVectorNumElements() == 1)
3127       // This must be an access of the only element.  Return it.
3128       Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0),
3129                          Node->getOperand(0));
3130     else
3131       Tmp1 = ExpandExtractFromVectorThroughStack(SDValue(Node, 0));
3132     Results.push_back(Tmp1);
3133     break;
3134   case ISD::EXTRACT_SUBVECTOR:
3135     Results.push_back(ExpandExtractFromVectorThroughStack(SDValue(Node, 0)));
3136     break;
3137   case ISD::INSERT_SUBVECTOR:
3138     Results.push_back(ExpandInsertToVectorThroughStack(SDValue(Node, 0)));
3139     break;
3140   case ISD::CONCAT_VECTORS:
3141     Results.push_back(ExpandVectorBuildThroughStack(Node));
3142     break;
3143   case ISD::SCALAR_TO_VECTOR:
3144     Results.push_back(ExpandSCALAR_TO_VECTOR(Node));
3145     break;
3146   case ISD::INSERT_VECTOR_ELT:
3147     Results.push_back(ExpandINSERT_VECTOR_ELT(Node->getOperand(0),
3148                                               Node->getOperand(1),
3149                                               Node->getOperand(2), dl));
3150     break;
3151   case ISD::VECTOR_SHUFFLE: {
3152     SmallVector<int, 32> NewMask;
3153     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
3154 
3155     EVT VT = Node->getValueType(0);
3156     EVT EltVT = VT.getVectorElementType();
3157     SDValue Op0 = Node->getOperand(0);
3158     SDValue Op1 = Node->getOperand(1);
3159     if (!TLI.isTypeLegal(EltVT)) {
3160       EVT NewEltVT = TLI.getTypeToTransformTo(*DAG.getContext(), EltVT);
3161 
3162       // BUILD_VECTOR operands are allowed to be wider than the element type.
3163       // But if NewEltVT is smaller that EltVT the BUILD_VECTOR does not accept
3164       // it.
3165       if (NewEltVT.bitsLT(EltVT)) {
3166         // Convert shuffle node.
3167         // If original node was v4i64 and the new EltVT is i32,
3168         // cast operands to v8i32 and re-build the mask.
3169 
3170         // Calculate new VT, the size of the new VT should be equal to original.
3171         EVT NewVT =
3172             EVT::getVectorVT(*DAG.getContext(), NewEltVT,
3173                              VT.getSizeInBits() / NewEltVT.getSizeInBits());
3174         assert(NewVT.bitsEq(VT));
3175 
3176         // cast operands to new VT
3177         Op0 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op0);
3178         Op1 = DAG.getNode(ISD::BITCAST, dl, NewVT, Op1);
3179 
3180         // Convert the shuffle mask
3181         unsigned int factor =
3182                          NewVT.getVectorNumElements()/VT.getVectorNumElements();
3183 
3184         // EltVT gets smaller
3185         assert(factor > 0);
3186 
3187         for (unsigned i = 0; i < VT.getVectorNumElements(); ++i) {
3188           if (Mask[i] < 0) {
3189             for (unsigned fi = 0; fi < factor; ++fi)
3190               NewMask.push_back(Mask[i]);
3191           }
3192           else {
3193             for (unsigned fi = 0; fi < factor; ++fi)
3194               NewMask.push_back(Mask[i]*factor+fi);
3195           }
3196         }
3197         Mask = NewMask;
3198         VT = NewVT;
3199       }
3200       EltVT = NewEltVT;
3201     }
3202     unsigned NumElems = VT.getVectorNumElements();
3203     SmallVector<SDValue, 16> Ops;
3204     for (unsigned i = 0; i != NumElems; ++i) {
3205       if (Mask[i] < 0) {
3206         Ops.push_back(DAG.getUNDEF(EltVT));
3207         continue;
3208       }
3209       unsigned Idx = Mask[i];
3210       if (Idx < NumElems)
3211         Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op0,
3212                                   DAG.getVectorIdxConstant(Idx, dl)));
3213       else
3214         Ops.push_back(
3215             DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT, Op1,
3216                         DAG.getVectorIdxConstant(Idx - NumElems, dl)));
3217     }
3218 
3219     Tmp1 = DAG.getBuildVector(VT, dl, Ops);
3220     // We may have changed the BUILD_VECTOR type. Cast it back to the Node type.
3221     Tmp1 = DAG.getNode(ISD::BITCAST, dl, Node->getValueType(0), Tmp1);
3222     Results.push_back(Tmp1);
3223     break;
3224   }
3225   case ISD::EXTRACT_ELEMENT: {
3226     EVT OpTy = Node->getOperand(0).getValueType();
3227     if (cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue()) {
3228       // 1 -> Hi
3229       Tmp1 = DAG.getNode(ISD::SRL, dl, OpTy, Node->getOperand(0),
3230                          DAG.getConstant(OpTy.getSizeInBits() / 2, dl,
3231                                          TLI.getShiftAmountTy(
3232                                              Node->getOperand(0).getValueType(),
3233                                              DAG.getDataLayout())));
3234       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0), Tmp1);
3235     } else {
3236       // 0 -> Lo
3237       Tmp1 = DAG.getNode(ISD::TRUNCATE, dl, Node->getValueType(0),
3238                          Node->getOperand(0));
3239     }
3240     Results.push_back(Tmp1);
3241     break;
3242   }
3243   case ISD::STACKSAVE:
3244     // Expand to CopyFromReg if the target set
3245     // StackPointerRegisterToSaveRestore.
3246     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3247       Results.push_back(DAG.getCopyFromReg(Node->getOperand(0), dl, SP,
3248                                            Node->getValueType(0)));
3249       Results.push_back(Results[0].getValue(1));
3250     } else {
3251       Results.push_back(DAG.getUNDEF(Node->getValueType(0)));
3252       Results.push_back(Node->getOperand(0));
3253     }
3254     break;
3255   case ISD::STACKRESTORE:
3256     // Expand to CopyToReg if the target set
3257     // StackPointerRegisterToSaveRestore.
3258     if (unsigned SP = TLI.getStackPointerRegisterToSaveRestore()) {
3259       Results.push_back(DAG.getCopyToReg(Node->getOperand(0), dl, SP,
3260                                          Node->getOperand(1)));
3261     } else {
3262       Results.push_back(Node->getOperand(0));
3263     }
3264     break;
3265   case ISD::GET_DYNAMIC_AREA_OFFSET:
3266     Results.push_back(DAG.getConstant(0, dl, Node->getValueType(0)));
3267     Results.push_back(Results[0].getValue(0));
3268     break;
3269   case ISD::FCOPYSIGN:
3270     Results.push_back(ExpandFCOPYSIGN(Node));
3271     break;
3272   case ISD::FNEG:
3273     Results.push_back(ExpandFNEG(Node));
3274     break;
3275   case ISD::FABS:
3276     Results.push_back(ExpandFABS(Node));
3277     break;
3278   case ISD::SMIN:
3279   case ISD::SMAX:
3280   case ISD::UMIN:
3281   case ISD::UMAX: {
3282     // Expand Y = MAX(A, B) -> Y = (A > B) ? A : B
3283     ISD::CondCode Pred;
3284     switch (Node->getOpcode()) {
3285     default: llvm_unreachable("How did we get here?");
3286     case ISD::SMAX: Pred = ISD::SETGT; break;
3287     case ISD::SMIN: Pred = ISD::SETLT; break;
3288     case ISD::UMAX: Pred = ISD::SETUGT; break;
3289     case ISD::UMIN: Pred = ISD::SETULT; break;
3290     }
3291     Tmp1 = Node->getOperand(0);
3292     Tmp2 = Node->getOperand(1);
3293     Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp1, Tmp2, Pred);
3294     Results.push_back(Tmp1);
3295     break;
3296   }
3297   case ISD::FMINNUM:
3298   case ISD::FMAXNUM: {
3299     if (SDValue Expanded = TLI.expandFMINNUM_FMAXNUM(Node, DAG))
3300       Results.push_back(Expanded);
3301     break;
3302   }
3303   case ISD::FSIN:
3304   case ISD::FCOS: {
3305     EVT VT = Node->getValueType(0);
3306     // Turn fsin / fcos into ISD::FSINCOS node if there are a pair of fsin /
3307     // fcos which share the same operand and both are used.
3308     if ((TLI.isOperationLegalOrCustom(ISD::FSINCOS, VT) ||
3309          isSinCosLibcallAvailable(Node, TLI))
3310         && useSinCos(Node)) {
3311       SDVTList VTs = DAG.getVTList(VT, VT);
3312       Tmp1 = DAG.getNode(ISD::FSINCOS, dl, VTs, Node->getOperand(0));
3313       if (Node->getOpcode() == ISD::FCOS)
3314         Tmp1 = Tmp1.getValue(1);
3315       Results.push_back(Tmp1);
3316     }
3317     break;
3318   }
3319   case ISD::FMAD:
3320     llvm_unreachable("Illegal fmad should never be formed");
3321 
3322   case ISD::FP16_TO_FP:
3323     if (Node->getValueType(0) != MVT::f32) {
3324       // We can extend to types bigger than f32 in two steps without changing
3325       // the result. Since "f16 -> f32" is much more commonly available, give
3326       // CodeGen the option of emitting that before resorting to a libcall.
3327       SDValue Res =
3328           DAG.getNode(ISD::FP16_TO_FP, dl, MVT::f32, Node->getOperand(0));
3329       Results.push_back(
3330           DAG.getNode(ISD::FP_EXTEND, dl, Node->getValueType(0), Res));
3331     }
3332     break;
3333   case ISD::STRICT_FP16_TO_FP:
3334     if (Node->getValueType(0) != MVT::f32) {
3335       // We can extend to types bigger than f32 in two steps without changing
3336       // the result. Since "f16 -> f32" is much more commonly available, give
3337       // CodeGen the option of emitting that before resorting to a libcall.
3338       SDValue Res =
3339           DAG.getNode(ISD::STRICT_FP16_TO_FP, dl, {MVT::f32, MVT::Other},
3340                       {Node->getOperand(0), Node->getOperand(1)});
3341       Res = DAG.getNode(ISD::STRICT_FP_EXTEND, dl,
3342                         {Node->getValueType(0), MVT::Other},
3343                         {Res.getValue(1), Res});
3344       Results.push_back(Res);
3345       Results.push_back(Res.getValue(1));
3346     }
3347     break;
3348   case ISD::FP_TO_FP16:
3349     LLVM_DEBUG(dbgs() << "Legalizing FP_TO_FP16\n");
3350     if (!TLI.useSoftFloat() && TM.Options.UnsafeFPMath) {
3351       SDValue Op = Node->getOperand(0);
3352       MVT SVT = Op.getSimpleValueType();
3353       if ((SVT == MVT::f64 || SVT == MVT::f80) &&
3354           TLI.isOperationLegalOrCustom(ISD::FP_TO_FP16, MVT::f32)) {
3355         // Under fastmath, we can expand this node into a fround followed by
3356         // a float-half conversion.
3357         SDValue FloatVal = DAG.getNode(ISD::FP_ROUND, dl, MVT::f32, Op,
3358                                        DAG.getIntPtrConstant(0, dl));
3359         Results.push_back(
3360             DAG.getNode(ISD::FP_TO_FP16, dl, Node->getValueType(0), FloatVal));
3361       }
3362     }
3363     break;
3364   case ISD::ConstantFP: {
3365     ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Node);
3366     // Check to see if this FP immediate is already legal.
3367     // If this is a legal constant, turn it into a TargetConstantFP node.
3368     if (!TLI.isFPImmLegal(CFP->getValueAPF(), Node->getValueType(0),
3369                           DAG.shouldOptForSize()))
3370       Results.push_back(ExpandConstantFP(CFP, true));
3371     break;
3372   }
3373   case ISD::Constant: {
3374     ConstantSDNode *CP = cast<ConstantSDNode>(Node);
3375     Results.push_back(ExpandConstant(CP));
3376     break;
3377   }
3378   case ISD::FSUB: {
3379     EVT VT = Node->getValueType(0);
3380     if (TLI.isOperationLegalOrCustom(ISD::FADD, VT) &&
3381         TLI.isOperationLegalOrCustom(ISD::FNEG, VT)) {
3382       const SDNodeFlags Flags = Node->getFlags();
3383       Tmp1 = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(1));
3384       Tmp1 = DAG.getNode(ISD::FADD, dl, VT, Node->getOperand(0), Tmp1, Flags);
3385       Results.push_back(Tmp1);
3386     }
3387     break;
3388   }
3389   case ISD::SUB: {
3390     EVT VT = Node->getValueType(0);
3391     assert(TLI.isOperationLegalOrCustom(ISD::ADD, VT) &&
3392            TLI.isOperationLegalOrCustom(ISD::XOR, VT) &&
3393            "Don't know how to expand this subtraction!");
3394     Tmp1 = DAG.getNode(ISD::XOR, dl, VT, Node->getOperand(1),
3395                DAG.getConstant(APInt::getAllOnesValue(VT.getSizeInBits()), dl,
3396                                VT));
3397     Tmp1 = DAG.getNode(ISD::ADD, dl, VT, Tmp1, DAG.getConstant(1, dl, VT));
3398     Results.push_back(DAG.getNode(ISD::ADD, dl, VT, Node->getOperand(0), Tmp1));
3399     break;
3400   }
3401   case ISD::UREM:
3402   case ISD::SREM:
3403     if (TLI.expandREM(Node, Tmp1, DAG))
3404       Results.push_back(Tmp1);
3405     break;
3406   case ISD::UDIV:
3407   case ISD::SDIV: {
3408     bool isSigned = Node->getOpcode() == ISD::SDIV;
3409     unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;
3410     EVT VT = Node->getValueType(0);
3411     if (TLI.isOperationLegalOrCustom(DivRemOpc, VT)) {
3412       SDVTList VTs = DAG.getVTList(VT, VT);
3413       Tmp1 = DAG.getNode(DivRemOpc, dl, VTs, Node->getOperand(0),
3414                          Node->getOperand(1));
3415       Results.push_back(Tmp1);
3416     }
3417     break;
3418   }
3419   case ISD::MULHU:
3420   case ISD::MULHS: {
3421     unsigned ExpandOpcode =
3422         Node->getOpcode() == ISD::MULHU ? ISD::UMUL_LOHI : ISD::SMUL_LOHI;
3423     EVT VT = Node->getValueType(0);
3424     SDVTList VTs = DAG.getVTList(VT, VT);
3425 
3426     Tmp1 = DAG.getNode(ExpandOpcode, dl, VTs, Node->getOperand(0),
3427                        Node->getOperand(1));
3428     Results.push_back(Tmp1.getValue(1));
3429     break;
3430   }
3431   case ISD::UMUL_LOHI:
3432   case ISD::SMUL_LOHI: {
3433     SDValue LHS = Node->getOperand(0);
3434     SDValue RHS = Node->getOperand(1);
3435     MVT VT = LHS.getSimpleValueType();
3436     unsigned MULHOpcode =
3437         Node->getOpcode() == ISD::UMUL_LOHI ? ISD::MULHU : ISD::MULHS;
3438 
3439     if (TLI.isOperationLegalOrCustom(MULHOpcode, VT)) {
3440       Results.push_back(DAG.getNode(ISD::MUL, dl, VT, LHS, RHS));
3441       Results.push_back(DAG.getNode(MULHOpcode, dl, VT, LHS, RHS));
3442       break;
3443     }
3444 
3445     SmallVector<SDValue, 4> Halves;
3446     EVT HalfType = EVT(VT).getHalfSizedIntegerVT(*DAG.getContext());
3447     assert(TLI.isTypeLegal(HalfType));
3448     if (TLI.expandMUL_LOHI(Node->getOpcode(), VT, dl, LHS, RHS, Halves,
3449                            HalfType, DAG,
3450                            TargetLowering::MulExpansionKind::Always)) {
3451       for (unsigned i = 0; i < 2; ++i) {
3452         SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Halves[2 * i]);
3453         SDValue Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Halves[2 * i + 1]);
3454         SDValue Shift = DAG.getConstant(
3455             HalfType.getScalarSizeInBits(), dl,
3456             TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3457         Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3458         Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3459       }
3460       break;
3461     }
3462     break;
3463   }
3464   case ISD::MUL: {
3465     EVT VT = Node->getValueType(0);
3466     SDVTList VTs = DAG.getVTList(VT, VT);
3467     // See if multiply or divide can be lowered using two-result operations.
3468     // We just need the low half of the multiply; try both the signed
3469     // and unsigned forms. If the target supports both SMUL_LOHI and
3470     // UMUL_LOHI, form a preference by checking which forms of plain
3471     // MULH it supports.
3472     bool HasSMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::SMUL_LOHI, VT);
3473     bool HasUMUL_LOHI = TLI.isOperationLegalOrCustom(ISD::UMUL_LOHI, VT);
3474     bool HasMULHS = TLI.isOperationLegalOrCustom(ISD::MULHS, VT);
3475     bool HasMULHU = TLI.isOperationLegalOrCustom(ISD::MULHU, VT);
3476     unsigned OpToUse = 0;
3477     if (HasSMUL_LOHI && !HasMULHS) {
3478       OpToUse = ISD::SMUL_LOHI;
3479     } else if (HasUMUL_LOHI && !HasMULHU) {
3480       OpToUse = ISD::UMUL_LOHI;
3481     } else if (HasSMUL_LOHI) {
3482       OpToUse = ISD::SMUL_LOHI;
3483     } else if (HasUMUL_LOHI) {
3484       OpToUse = ISD::UMUL_LOHI;
3485     }
3486     if (OpToUse) {
3487       Results.push_back(DAG.getNode(OpToUse, dl, VTs, Node->getOperand(0),
3488                                     Node->getOperand(1)));
3489       break;
3490     }
3491 
3492     SDValue Lo, Hi;
3493     EVT HalfType = VT.getHalfSizedIntegerVT(*DAG.getContext());
3494     if (TLI.isOperationLegalOrCustom(ISD::ZERO_EXTEND, VT) &&
3495         TLI.isOperationLegalOrCustom(ISD::ANY_EXTEND, VT) &&
3496         TLI.isOperationLegalOrCustom(ISD::SHL, VT) &&
3497         TLI.isOperationLegalOrCustom(ISD::OR, VT) &&
3498         TLI.expandMUL(Node, Lo, Hi, HalfType, DAG,
3499                       TargetLowering::MulExpansionKind::OnlyLegalOrCustom)) {
3500       Lo = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, Lo);
3501       Hi = DAG.getNode(ISD::ANY_EXTEND, dl, VT, Hi);
3502       SDValue Shift =
3503           DAG.getConstant(HalfType.getSizeInBits(), dl,
3504                           TLI.getShiftAmountTy(HalfType, DAG.getDataLayout()));
3505       Hi = DAG.getNode(ISD::SHL, dl, VT, Hi, Shift);
3506       Results.push_back(DAG.getNode(ISD::OR, dl, VT, Lo, Hi));
3507     }
3508     break;
3509   }
3510   case ISD::FSHL:
3511   case ISD::FSHR:
3512     if (TLI.expandFunnelShift(Node, Tmp1, DAG))
3513       Results.push_back(Tmp1);
3514     break;
3515   case ISD::ROTL:
3516   case ISD::ROTR:
3517     if (TLI.expandROT(Node, Tmp1, DAG))
3518       Results.push_back(Tmp1);
3519     break;
3520   case ISD::SADDSAT:
3521   case ISD::UADDSAT:
3522   case ISD::SSUBSAT:
3523   case ISD::USUBSAT:
3524     Results.push_back(TLI.expandAddSubSat(Node, DAG));
3525     break;
3526   case ISD::SSHLSAT:
3527   case ISD::USHLSAT:
3528     Results.push_back(TLI.expandShlSat(Node, DAG));
3529     break;
3530   case ISD::SMULFIX:
3531   case ISD::SMULFIXSAT:
3532   case ISD::UMULFIX:
3533   case ISD::UMULFIXSAT:
3534     Results.push_back(TLI.expandFixedPointMul(Node, DAG));
3535     break;
3536   case ISD::SDIVFIX:
3537   case ISD::SDIVFIXSAT:
3538   case ISD::UDIVFIX:
3539   case ISD::UDIVFIXSAT:
3540     if (SDValue V = TLI.expandFixedPointDiv(Node->getOpcode(), SDLoc(Node),
3541                                             Node->getOperand(0),
3542                                             Node->getOperand(1),
3543                                             Node->getConstantOperandVal(2),
3544                                             DAG)) {
3545       Results.push_back(V);
3546       break;
3547     }
3548     // FIXME: We might want to retry here with a wider type if we fail, if that
3549     // type is legal.
3550     // FIXME: Technically, so long as we only have sdivfixes where BW+Scale is
3551     // <= 128 (which is the case for all of the default Embedded-C types),
3552     // we will only get here with types and scales that we could always expand
3553     // if we were allowed to generate libcalls to division functions of illegal
3554     // type. But we cannot do that.
3555     llvm_unreachable("Cannot expand DIVFIX!");
3556   case ISD::ADDCARRY:
3557   case ISD::SUBCARRY: {
3558     SDValue LHS = Node->getOperand(0);
3559     SDValue RHS = Node->getOperand(1);
3560     SDValue Carry = Node->getOperand(2);
3561 
3562     bool IsAdd = Node->getOpcode() == ISD::ADDCARRY;
3563 
3564     // Initial add of the 2 operands.
3565     unsigned Op = IsAdd ? ISD::ADD : ISD::SUB;
3566     EVT VT = LHS.getValueType();
3567     SDValue Sum = DAG.getNode(Op, dl, VT, LHS, RHS);
3568 
3569     // Initial check for overflow.
3570     EVT CarryType = Node->getValueType(1);
3571     EVT SetCCType = getSetCCResultType(Node->getValueType(0));
3572     ISD::CondCode CC = IsAdd ? ISD::SETULT : ISD::SETUGT;
3573     SDValue Overflow = DAG.getSetCC(dl, SetCCType, Sum, LHS, CC);
3574 
3575     // Add of the sum and the carry.
3576     SDValue One = DAG.getConstant(1, dl, VT);
3577     SDValue CarryExt =
3578         DAG.getNode(ISD::AND, dl, VT, DAG.getZExtOrTrunc(Carry, dl, VT), One);
3579     SDValue Sum2 = DAG.getNode(Op, dl, VT, Sum, CarryExt);
3580 
3581     // Second check for overflow. If we are adding, we can only overflow if the
3582     // initial sum is all 1s ang the carry is set, resulting in a new sum of 0.
3583     // If we are subtracting, we can only overflow if the initial sum is 0 and
3584     // the carry is set, resulting in a new sum of all 1s.
3585     SDValue Zero = DAG.getConstant(0, dl, VT);
3586     SDValue Overflow2 =
3587         IsAdd ? DAG.getSetCC(dl, SetCCType, Sum2, Zero, ISD::SETEQ)
3588               : DAG.getSetCC(dl, SetCCType, Sum, Zero, ISD::SETEQ);
3589     Overflow2 = DAG.getNode(ISD::AND, dl, SetCCType, Overflow2,
3590                             DAG.getZExtOrTrunc(Carry, dl, SetCCType));
3591 
3592     SDValue ResultCarry =
3593         DAG.getNode(ISD::OR, dl, SetCCType, Overflow, Overflow2);
3594 
3595     Results.push_back(Sum2);
3596     Results.push_back(DAG.getBoolExtOrTrunc(ResultCarry, dl, CarryType, VT));
3597     break;
3598   }
3599   case ISD::SADDO:
3600   case ISD::SSUBO: {
3601     SDValue Result, Overflow;
3602     TLI.expandSADDSUBO(Node, Result, Overflow, DAG);
3603     Results.push_back(Result);
3604     Results.push_back(Overflow);
3605     break;
3606   }
3607   case ISD::UADDO:
3608   case ISD::USUBO: {
3609     SDValue Result, Overflow;
3610     TLI.expandUADDSUBO(Node, Result, Overflow, DAG);
3611     Results.push_back(Result);
3612     Results.push_back(Overflow);
3613     break;
3614   }
3615   case ISD::UMULO:
3616   case ISD::SMULO: {
3617     SDValue Result, Overflow;
3618     if (TLI.expandMULO(Node, Result, Overflow, DAG)) {
3619       Results.push_back(Result);
3620       Results.push_back(Overflow);
3621     }
3622     break;
3623   }
3624   case ISD::BUILD_PAIR: {
3625     EVT PairTy = Node->getValueType(0);
3626     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, PairTy, Node->getOperand(0));
3627     Tmp2 = DAG.getNode(ISD::ANY_EXTEND, dl, PairTy, Node->getOperand(1));
3628     Tmp2 = DAG.getNode(
3629         ISD::SHL, dl, PairTy, Tmp2,
3630         DAG.getConstant(PairTy.getSizeInBits() / 2, dl,
3631                         TLI.getShiftAmountTy(PairTy, DAG.getDataLayout())));
3632     Results.push_back(DAG.getNode(ISD::OR, dl, PairTy, Tmp1, Tmp2));
3633     break;
3634   }
3635   case ISD::SELECT:
3636     Tmp1 = Node->getOperand(0);
3637     Tmp2 = Node->getOperand(1);
3638     Tmp3 = Node->getOperand(2);
3639     if (Tmp1.getOpcode() == ISD::SETCC) {
3640       Tmp1 = DAG.getSelectCC(dl, Tmp1.getOperand(0), Tmp1.getOperand(1),
3641                              Tmp2, Tmp3,
3642                              cast<CondCodeSDNode>(Tmp1.getOperand(2))->get());
3643     } else {
3644       Tmp1 = DAG.getSelectCC(dl, Tmp1,
3645                              DAG.getConstant(0, dl, Tmp1.getValueType()),
3646                              Tmp2, Tmp3, ISD::SETNE);
3647     }
3648     Tmp1->setFlags(Node->getFlags());
3649     Results.push_back(Tmp1);
3650     break;
3651   case ISD::BR_JT: {
3652     SDValue Chain = Node->getOperand(0);
3653     SDValue Table = Node->getOperand(1);
3654     SDValue Index = Node->getOperand(2);
3655 
3656     const DataLayout &TD = DAG.getDataLayout();
3657     EVT PTy = TLI.getPointerTy(TD);
3658 
3659     unsigned EntrySize =
3660       DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
3661 
3662     // For power-of-two jumptable entry sizes convert multiplication to a shift.
3663     // This transformation needs to be done here since otherwise the MIPS
3664     // backend will end up emitting a three instruction multiply sequence
3665     // instead of a single shift and MSP430 will call a runtime function.
3666     if (llvm::isPowerOf2_32(EntrySize))
3667       Index = DAG.getNode(
3668           ISD::SHL, dl, Index.getValueType(), Index,
3669           DAG.getConstant(llvm::Log2_32(EntrySize), dl, Index.getValueType()));
3670     else
3671       Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index,
3672                           DAG.getConstant(EntrySize, dl, Index.getValueType()));
3673     SDValue Addr = DAG.getNode(ISD::ADD, dl, Index.getValueType(),
3674                                Index, Table);
3675 
3676     EVT MemVT = EVT::getIntegerVT(*DAG.getContext(), EntrySize * 8);
3677     SDValue LD = DAG.getExtLoad(
3678         ISD::SEXTLOAD, dl, PTy, Chain, Addr,
3679         MachinePointerInfo::getJumpTable(DAG.getMachineFunction()), MemVT);
3680     Addr = LD;
3681     if (TLI.isJumpTableRelative()) {
3682       // For PIC, the sequence is:
3683       // BRIND(load(Jumptable + index) + RelocBase)
3684       // RelocBase can be JumpTable, GOT or some sort of global base.
3685       Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr,
3686                           TLI.getPICJumpTableRelocBase(Table, DAG));
3687     }
3688 
3689     Tmp1 = TLI.expandIndirectJTBranch(dl, LD.getValue(1), Addr, DAG);
3690     Results.push_back(Tmp1);
3691     break;
3692   }
3693   case ISD::BRCOND:
3694     // Expand brcond's setcc into its constituent parts and create a BR_CC
3695     // Node.
3696     Tmp1 = Node->getOperand(0);
3697     Tmp2 = Node->getOperand(1);
3698     if (Tmp2.getOpcode() == ISD::SETCC) {
3699       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other,
3700                          Tmp1, Tmp2.getOperand(2),
3701                          Tmp2.getOperand(0), Tmp2.getOperand(1),
3702                          Node->getOperand(2));
3703     } else {
3704       // We test only the i1 bit.  Skip the AND if UNDEF or another AND.
3705       if (Tmp2.isUndef() ||
3706           (Tmp2.getOpcode() == ISD::AND &&
3707            isa<ConstantSDNode>(Tmp2.getOperand(1)) &&
3708            cast<ConstantSDNode>(Tmp2.getOperand(1))->getZExtValue() == 1))
3709         Tmp3 = Tmp2;
3710       else
3711         Tmp3 = DAG.getNode(ISD::AND, dl, Tmp2.getValueType(), Tmp2,
3712                            DAG.getConstant(1, dl, Tmp2.getValueType()));
3713       Tmp1 = DAG.getNode(ISD::BR_CC, dl, MVT::Other, Tmp1,
3714                          DAG.getCondCode(ISD::SETNE), Tmp3,
3715                          DAG.getConstant(0, dl, Tmp3.getValueType()),
3716                          Node->getOperand(2));
3717     }
3718     Results.push_back(Tmp1);
3719     break;
3720   case ISD::SETCC:
3721   case ISD::STRICT_FSETCC:
3722   case ISD::STRICT_FSETCCS: {
3723     bool IsStrict = Node->getOpcode() != ISD::SETCC;
3724     bool IsSignaling = Node->getOpcode() == ISD::STRICT_FSETCCS;
3725     SDValue Chain = IsStrict ? Node->getOperand(0) : SDValue();
3726     unsigned Offset = IsStrict ? 1 : 0;
3727     Tmp1 = Node->getOperand(0 + Offset);
3728     Tmp2 = Node->getOperand(1 + Offset);
3729     Tmp3 = Node->getOperand(2 + Offset);
3730     bool Legalized =
3731         LegalizeSetCCCondCode(Node->getValueType(0), Tmp1, Tmp2, Tmp3,
3732                               NeedInvert, dl, Chain, IsSignaling);
3733 
3734     if (Legalized) {
3735       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3736       // condition code, create a new SETCC node.
3737       if (Tmp3.getNode())
3738         Tmp1 = DAG.getNode(ISD::SETCC, dl, Node->getValueType(0),
3739                            Tmp1, Tmp2, Tmp3, Node->getFlags());
3740 
3741       // If we expanded the SETCC by inverting the condition code, then wrap
3742       // the existing SETCC in a NOT to restore the intended condition.
3743       if (NeedInvert)
3744         Tmp1 = DAG.getLogicalNOT(dl, Tmp1, Tmp1->getValueType(0));
3745 
3746       Results.push_back(Tmp1);
3747       if (IsStrict)
3748         Results.push_back(Chain);
3749 
3750       break;
3751     }
3752 
3753     // FIXME: It seems Legalized is false iff CCCode is Legal. I don't
3754     // understand if this code is useful for strict nodes.
3755     assert(!IsStrict && "Don't know how to expand for strict nodes.");
3756 
3757     // Otherwise, SETCC for the given comparison type must be completely
3758     // illegal; expand it into a SELECT_CC.
3759     EVT VT = Node->getValueType(0);
3760     int TrueValue;
3761     switch (TLI.getBooleanContents(Tmp1.getValueType())) {
3762     case TargetLowering::ZeroOrOneBooleanContent:
3763     case TargetLowering::UndefinedBooleanContent:
3764       TrueValue = 1;
3765       break;
3766     case TargetLowering::ZeroOrNegativeOneBooleanContent:
3767       TrueValue = -1;
3768       break;
3769     }
3770     Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, VT, Tmp1, Tmp2,
3771                        DAG.getConstant(TrueValue, dl, VT),
3772                        DAG.getConstant(0, dl, VT),
3773                        Tmp3);
3774     Tmp1->setFlags(Node->getFlags());
3775     Results.push_back(Tmp1);
3776     break;
3777   }
3778   case ISD::SELECT_CC: {
3779     // TODO: need to add STRICT_SELECT_CC and STRICT_SELECT_CCS
3780     Tmp1 = Node->getOperand(0);   // LHS
3781     Tmp2 = Node->getOperand(1);   // RHS
3782     Tmp3 = Node->getOperand(2);   // True
3783     Tmp4 = Node->getOperand(3);   // False
3784     EVT VT = Node->getValueType(0);
3785     SDValue Chain;
3786     SDValue CC = Node->getOperand(4);
3787     ISD::CondCode CCOp = cast<CondCodeSDNode>(CC)->get();
3788 
3789     if (TLI.isCondCodeLegalOrCustom(CCOp, Tmp1.getSimpleValueType())) {
3790       // If the condition code is legal, then we need to expand this
3791       // node using SETCC and SELECT.
3792       EVT CmpVT = Tmp1.getValueType();
3793       assert(!TLI.isOperationExpand(ISD::SELECT, VT) &&
3794              "Cannot expand ISD::SELECT_CC when ISD::SELECT also needs to be "
3795              "expanded.");
3796       EVT CCVT = getSetCCResultType(CmpVT);
3797       SDValue Cond = DAG.getNode(ISD::SETCC, dl, CCVT, Tmp1, Tmp2, CC, Node->getFlags());
3798       Results.push_back(DAG.getSelect(dl, VT, Cond, Tmp3, Tmp4));
3799       break;
3800     }
3801 
3802     // SELECT_CC is legal, so the condition code must not be.
3803     bool Legalized = false;
3804     // Try to legalize by inverting the condition.  This is for targets that
3805     // might support an ordered version of a condition, but not the unordered
3806     // version (or vice versa).
3807     ISD::CondCode InvCC = ISD::getSetCCInverse(CCOp, Tmp1.getValueType());
3808     if (TLI.isCondCodeLegalOrCustom(InvCC, Tmp1.getSimpleValueType())) {
3809       // Use the new condition code and swap true and false
3810       Legalized = true;
3811       Tmp1 = DAG.getSelectCC(dl, Tmp1, Tmp2, Tmp4, Tmp3, InvCC);
3812       Tmp1->setFlags(Node->getFlags());
3813     } else {
3814       // If The inverse is not legal, then try to swap the arguments using
3815       // the inverse condition code.
3816       ISD::CondCode SwapInvCC = ISD::getSetCCSwappedOperands(InvCC);
3817       if (TLI.isCondCodeLegalOrCustom(SwapInvCC, Tmp1.getSimpleValueType())) {
3818         // The swapped inverse condition is legal, so swap true and false,
3819         // lhs and rhs.
3820         Legalized = true;
3821         Tmp1 = DAG.getSelectCC(dl, Tmp2, Tmp1, Tmp4, Tmp3, SwapInvCC);
3822         Tmp1->setFlags(Node->getFlags());
3823       }
3824     }
3825 
3826     if (!Legalized) {
3827       Legalized = LegalizeSetCCCondCode(getSetCCResultType(Tmp1.getValueType()),
3828                                         Tmp1, Tmp2, CC, NeedInvert, dl, Chain);
3829 
3830       assert(Legalized && "Can't legalize SELECT_CC with legal condition!");
3831 
3832       // If we expanded the SETCC by inverting the condition code, then swap
3833       // the True/False operands to match.
3834       if (NeedInvert)
3835         std::swap(Tmp3, Tmp4);
3836 
3837       // If we expanded the SETCC by swapping LHS and RHS, or by inverting the
3838       // condition code, create a new SELECT_CC node.
3839       if (CC.getNode()) {
3840         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0),
3841                            Tmp1, Tmp2, Tmp3, Tmp4, CC);
3842       } else {
3843         Tmp2 = DAG.getConstant(0, dl, Tmp1.getValueType());
3844         CC = DAG.getCondCode(ISD::SETNE);
3845         Tmp1 = DAG.getNode(ISD::SELECT_CC, dl, Node->getValueType(0), Tmp1,
3846                            Tmp2, Tmp3, Tmp4, CC);
3847       }
3848       Tmp1->setFlags(Node->getFlags());
3849     }
3850     Results.push_back(Tmp1);
3851     break;
3852   }
3853   case ISD::BR_CC: {
3854     // TODO: need to add STRICT_BR_CC and STRICT_BR_CCS
3855     SDValue Chain;
3856     Tmp1 = Node->getOperand(0);              // Chain
3857     Tmp2 = Node->getOperand(2);              // LHS
3858     Tmp3 = Node->getOperand(3);              // RHS
3859     Tmp4 = Node->getOperand(1);              // CC
3860 
3861     bool Legalized =
3862         LegalizeSetCCCondCode(getSetCCResultType(Tmp2.getValueType()), Tmp2,
3863                               Tmp3, Tmp4, NeedInvert, dl, Chain);
3864     (void)Legalized;
3865     assert(Legalized && "Can't legalize BR_CC with legal condition!");
3866 
3867     assert(!NeedInvert && "Don't know how to invert BR_CC!");
3868 
3869     // If we expanded the SETCC by swapping LHS and RHS, create a new BR_CC
3870     // node.
3871     if (Tmp4.getNode()) {
3872       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1,
3873                          Tmp4, Tmp2, Tmp3, Node->getOperand(4));
3874     } else {
3875       Tmp3 = DAG.getConstant(0, dl, Tmp2.getValueType());
3876       Tmp4 = DAG.getCondCode(ISD::SETNE);
3877       Tmp1 = DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0), Tmp1, Tmp4,
3878                          Tmp2, Tmp3, Node->getOperand(4));
3879     }
3880     Results.push_back(Tmp1);
3881     break;
3882   }
3883   case ISD::BUILD_VECTOR:
3884     Results.push_back(ExpandBUILD_VECTOR(Node));
3885     break;
3886   case ISD::SPLAT_VECTOR:
3887     Results.push_back(ExpandSPLAT_VECTOR(Node));
3888     break;
3889   case ISD::SRA:
3890   case ISD::SRL:
3891   case ISD::SHL: {
3892     // Scalarize vector SRA/SRL/SHL.
3893     EVT VT = Node->getValueType(0);
3894     assert(VT.isVector() && "Unable to legalize non-vector shift");
3895     assert(TLI.isTypeLegal(VT.getScalarType())&& "Element type must be legal");
3896     unsigned NumElem = VT.getVectorNumElements();
3897 
3898     SmallVector<SDValue, 8> Scalars;
3899     for (unsigned Idx = 0; Idx < NumElem; Idx++) {
3900       SDValue Ex =
3901           DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(),
3902                       Node->getOperand(0), DAG.getVectorIdxConstant(Idx, dl));
3903       SDValue Sh =
3904           DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, VT.getScalarType(),
3905                       Node->getOperand(1), DAG.getVectorIdxConstant(Idx, dl));
3906       Scalars.push_back(DAG.getNode(Node->getOpcode(), dl,
3907                                     VT.getScalarType(), Ex, Sh));
3908     }
3909 
3910     SDValue Result = DAG.getBuildVector(Node->getValueType(0), dl, Scalars);
3911     Results.push_back(Result);
3912     break;
3913   }
3914   case ISD::VECREDUCE_FADD:
3915   case ISD::VECREDUCE_FMUL:
3916   case ISD::VECREDUCE_ADD:
3917   case ISD::VECREDUCE_MUL:
3918   case ISD::VECREDUCE_AND:
3919   case ISD::VECREDUCE_OR:
3920   case ISD::VECREDUCE_XOR:
3921   case ISD::VECREDUCE_SMAX:
3922   case ISD::VECREDUCE_SMIN:
3923   case ISD::VECREDUCE_UMAX:
3924   case ISD::VECREDUCE_UMIN:
3925   case ISD::VECREDUCE_FMAX:
3926   case ISD::VECREDUCE_FMIN:
3927     Results.push_back(TLI.expandVecReduce(Node, DAG));
3928     break;
3929   case ISD::GLOBAL_OFFSET_TABLE:
3930   case ISD::GlobalAddress:
3931   case ISD::GlobalTLSAddress:
3932   case ISD::ExternalSymbol:
3933   case ISD::ConstantPool:
3934   case ISD::JumpTable:
3935   case ISD::INTRINSIC_W_CHAIN:
3936   case ISD::INTRINSIC_WO_CHAIN:
3937   case ISD::INTRINSIC_VOID:
3938     // FIXME: Custom lowering for these operations shouldn't return null!
3939     // Return true so that we don't call ConvertNodeToLibcall which also won't
3940     // do anything.
3941     return true;
3942   }
3943 
3944   if (!TLI.isStrictFPEnabled() && Results.empty() && Node->isStrictFPOpcode()) {
3945     // FIXME: We were asked to expand a strict floating-point operation,
3946     // but there is currently no expansion implemented that would preserve
3947     // the "strict" properties.  For now, we just fall back to the non-strict
3948     // version if that is legal on the target.  The actual mutation of the
3949     // operation will happen in SelectionDAGISel::DoInstructionSelection.
3950     switch (Node->getOpcode()) {
3951     default:
3952       if (TLI.getStrictFPOperationAction(Node->getOpcode(),
3953                                          Node->getValueType(0))
3954           == TargetLowering::Legal)
3955         return true;
3956       break;
3957     case ISD::STRICT_FSUB: {
3958       if (TLI.getStrictFPOperationAction(
3959               ISD::STRICT_FSUB, Node->getValueType(0)) == TargetLowering::Legal)
3960         return true;
3961       if (TLI.getStrictFPOperationAction(
3962               ISD::STRICT_FADD, Node->getValueType(0)) != TargetLowering::Legal)
3963         break;
3964 
3965       EVT VT = Node->getValueType(0);
3966       const SDNodeFlags Flags = Node->getFlags();
3967       SDValue Neg = DAG.getNode(ISD::FNEG, dl, VT, Node->getOperand(2), Flags);
3968       SDValue Fadd = DAG.getNode(ISD::STRICT_FADD, dl, Node->getVTList(),
3969                                  {Node->getOperand(0), Node->getOperand(1), Neg},
3970                          Flags);
3971 
3972       Results.push_back(Fadd);
3973       Results.push_back(Fadd.getValue(1));
3974       break;
3975     }
3976     case ISD::STRICT_LRINT:
3977     case ISD::STRICT_LLRINT:
3978     case ISD::STRICT_LROUND:
3979     case ISD::STRICT_LLROUND:
3980       // These are registered by the operand type instead of the value
3981       // type. Reflect that here.
3982       if (TLI.getStrictFPOperationAction(Node->getOpcode(),
3983                                          Node->getOperand(1).getValueType())
3984           == TargetLowering::Legal)
3985         return true;
3986       break;
3987     }
3988   }
3989 
3990   // Replace the original node with the legalized result.
3991   if (Results.empty()) {
3992     LLVM_DEBUG(dbgs() << "Cannot expand node\n");
3993     return false;
3994   }
3995 
3996   LLVM_DEBUG(dbgs() << "Successfully expanded node\n");
3997   ReplaceNode(Node, Results.data());
3998   return true;
3999 }
4000 
4001 void SelectionDAGLegalize::ConvertNodeToLibcall(SDNode *Node) {
4002   LLVM_DEBUG(dbgs() << "Trying to convert node to libcall\n");
4003   SmallVector<SDValue, 8> Results;
4004   SDLoc dl(Node);
4005   // FIXME: Check flags on the node to see if we can use a finite call.
4006   unsigned Opc = Node->getOpcode();
4007   switch (Opc) {
4008   case ISD::ATOMIC_FENCE: {
4009     // If the target didn't lower this, lower it to '__sync_synchronize()' call
4010     // FIXME: handle "fence singlethread" more efficiently.
4011     TargetLowering::ArgListTy Args;
4012 
4013     TargetLowering::CallLoweringInfo CLI(DAG);
4014     CLI.setDebugLoc(dl)
4015         .setChain(Node->getOperand(0))
4016         .setLibCallee(
4017             CallingConv::C, Type::getVoidTy(*DAG.getContext()),
4018             DAG.getExternalSymbol("__sync_synchronize",
4019                                   TLI.getPointerTy(DAG.getDataLayout())),
4020             std::move(Args));
4021 
4022     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
4023 
4024     Results.push_back(CallResult.second);
4025     break;
4026   }
4027   // By default, atomic intrinsics are marked Legal and lowered. Targets
4028   // which don't support them directly, however, may want libcalls, in which
4029   // case they mark them Expand, and we get here.
4030   case ISD::ATOMIC_SWAP:
4031   case ISD::ATOMIC_LOAD_ADD:
4032   case ISD::ATOMIC_LOAD_SUB:
4033   case ISD::ATOMIC_LOAD_AND:
4034   case ISD::ATOMIC_LOAD_CLR:
4035   case ISD::ATOMIC_LOAD_OR:
4036   case ISD::ATOMIC_LOAD_XOR:
4037   case ISD::ATOMIC_LOAD_NAND:
4038   case ISD::ATOMIC_LOAD_MIN:
4039   case ISD::ATOMIC_LOAD_MAX:
4040   case ISD::ATOMIC_LOAD_UMIN:
4041   case ISD::ATOMIC_LOAD_UMAX:
4042   case ISD::ATOMIC_CMP_SWAP: {
4043     MVT VT = cast<AtomicSDNode>(Node)->getMemoryVT().getSimpleVT();
4044     RTLIB::Libcall LC = RTLIB::getSYNC(Opc, VT);
4045     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unexpected atomic op or value type!");
4046 
4047     EVT RetVT = Node->getValueType(0);
4048     SmallVector<SDValue, 4> Ops(Node->op_begin() + 1, Node->op_end());
4049     TargetLowering::MakeLibCallOptions CallOptions;
4050     std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(DAG, LC, RetVT,
4051                                                       Ops, CallOptions,
4052                                                       SDLoc(Node),
4053                                                       Node->getOperand(0));
4054     Results.push_back(Tmp.first);
4055     Results.push_back(Tmp.second);
4056     break;
4057   }
4058   case ISD::TRAP: {
4059     // If this operation is not supported, lower it to 'abort()' call
4060     TargetLowering::ArgListTy Args;
4061     TargetLowering::CallLoweringInfo CLI(DAG);
4062     CLI.setDebugLoc(dl)
4063         .setChain(Node->getOperand(0))
4064         .setLibCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
4065                       DAG.getExternalSymbol(
4066                           "abort", TLI.getPointerTy(DAG.getDataLayout())),
4067                       std::move(Args));
4068     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
4069 
4070     Results.push_back(CallResult.second);
4071     break;
4072   }
4073   case ISD::FMINNUM:
4074   case ISD::STRICT_FMINNUM:
4075     ExpandFPLibCall(Node, RTLIB::FMIN_F32, RTLIB::FMIN_F64,
4076                     RTLIB::FMIN_F80, RTLIB::FMIN_F128,
4077                     RTLIB::FMIN_PPCF128, Results);
4078     break;
4079   case ISD::FMAXNUM:
4080   case ISD::STRICT_FMAXNUM:
4081     ExpandFPLibCall(Node, RTLIB::FMAX_F32, RTLIB::FMAX_F64,
4082                     RTLIB::FMAX_F80, RTLIB::FMAX_F128,
4083                     RTLIB::FMAX_PPCF128, Results);
4084     break;
4085   case ISD::FSQRT:
4086   case ISD::STRICT_FSQRT:
4087     ExpandFPLibCall(Node, RTLIB::SQRT_F32, RTLIB::SQRT_F64,
4088                     RTLIB::SQRT_F80, RTLIB::SQRT_F128,
4089                     RTLIB::SQRT_PPCF128, Results);
4090     break;
4091   case ISD::FCBRT:
4092     ExpandFPLibCall(Node, RTLIB::CBRT_F32, RTLIB::CBRT_F64,
4093                     RTLIB::CBRT_F80, RTLIB::CBRT_F128,
4094                     RTLIB::CBRT_PPCF128, Results);
4095     break;
4096   case ISD::FSIN:
4097   case ISD::STRICT_FSIN:
4098     ExpandFPLibCall(Node, RTLIB::SIN_F32, RTLIB::SIN_F64,
4099                     RTLIB::SIN_F80, RTLIB::SIN_F128,
4100                     RTLIB::SIN_PPCF128, Results);
4101     break;
4102   case ISD::FCOS:
4103   case ISD::STRICT_FCOS:
4104     ExpandFPLibCall(Node, RTLIB::COS_F32, RTLIB::COS_F64,
4105                     RTLIB::COS_F80, RTLIB::COS_F128,
4106                     RTLIB::COS_PPCF128, Results);
4107     break;
4108   case ISD::FSINCOS:
4109     // Expand into sincos libcall.
4110     ExpandSinCosLibCall(Node, Results);
4111     break;
4112   case ISD::FLOG:
4113   case ISD::STRICT_FLOG:
4114     ExpandFPLibCall(Node, RTLIB::LOG_F32, RTLIB::LOG_F64, RTLIB::LOG_F80,
4115                     RTLIB::LOG_F128, RTLIB::LOG_PPCF128, Results);
4116     break;
4117   case ISD::FLOG2:
4118   case ISD::STRICT_FLOG2:
4119     ExpandFPLibCall(Node, RTLIB::LOG2_F32, RTLIB::LOG2_F64, RTLIB::LOG2_F80,
4120                     RTLIB::LOG2_F128, RTLIB::LOG2_PPCF128, Results);
4121     break;
4122   case ISD::FLOG10:
4123   case ISD::STRICT_FLOG10:
4124     ExpandFPLibCall(Node, RTLIB::LOG10_F32, RTLIB::LOG10_F64, RTLIB::LOG10_F80,
4125                     RTLIB::LOG10_F128, RTLIB::LOG10_PPCF128, Results);
4126     break;
4127   case ISD::FEXP:
4128   case ISD::STRICT_FEXP:
4129     ExpandFPLibCall(Node, RTLIB::EXP_F32, RTLIB::EXP_F64, RTLIB::EXP_F80,
4130                     RTLIB::EXP_F128, RTLIB::EXP_PPCF128, Results);
4131     break;
4132   case ISD::FEXP2:
4133   case ISD::STRICT_FEXP2:
4134     ExpandFPLibCall(Node, RTLIB::EXP2_F32, RTLIB::EXP2_F64, RTLIB::EXP2_F80,
4135                     RTLIB::EXP2_F128, RTLIB::EXP2_PPCF128, Results);
4136     break;
4137   case ISD::FTRUNC:
4138   case ISD::STRICT_FTRUNC:
4139     ExpandFPLibCall(Node, RTLIB::TRUNC_F32, RTLIB::TRUNC_F64,
4140                     RTLIB::TRUNC_F80, RTLIB::TRUNC_F128,
4141                     RTLIB::TRUNC_PPCF128, Results);
4142     break;
4143   case ISD::FFLOOR:
4144   case ISD::STRICT_FFLOOR:
4145     ExpandFPLibCall(Node, RTLIB::FLOOR_F32, RTLIB::FLOOR_F64,
4146                     RTLIB::FLOOR_F80, RTLIB::FLOOR_F128,
4147                     RTLIB::FLOOR_PPCF128, Results);
4148     break;
4149   case ISD::FCEIL:
4150   case ISD::STRICT_FCEIL:
4151     ExpandFPLibCall(Node, RTLIB::CEIL_F32, RTLIB::CEIL_F64,
4152                     RTLIB::CEIL_F80, RTLIB::CEIL_F128,
4153                     RTLIB::CEIL_PPCF128, Results);
4154     break;
4155   case ISD::FRINT:
4156   case ISD::STRICT_FRINT:
4157     ExpandFPLibCall(Node, RTLIB::RINT_F32, RTLIB::RINT_F64,
4158                     RTLIB::RINT_F80, RTLIB::RINT_F128,
4159                     RTLIB::RINT_PPCF128, Results);
4160     break;
4161   case ISD::FNEARBYINT:
4162   case ISD::STRICT_FNEARBYINT:
4163     ExpandFPLibCall(Node, RTLIB::NEARBYINT_F32,
4164                     RTLIB::NEARBYINT_F64,
4165                     RTLIB::NEARBYINT_F80,
4166                     RTLIB::NEARBYINT_F128,
4167                     RTLIB::NEARBYINT_PPCF128, Results);
4168     break;
4169   case ISD::FROUND:
4170   case ISD::STRICT_FROUND:
4171     ExpandFPLibCall(Node, RTLIB::ROUND_F32,
4172                     RTLIB::ROUND_F64,
4173                     RTLIB::ROUND_F80,
4174                     RTLIB::ROUND_F128,
4175                     RTLIB::ROUND_PPCF128, Results);
4176     break;
4177   case ISD::FROUNDEVEN:
4178   case ISD::STRICT_FROUNDEVEN:
4179     ExpandFPLibCall(Node, RTLIB::ROUNDEVEN_F32,
4180                     RTLIB::ROUNDEVEN_F64,
4181                     RTLIB::ROUNDEVEN_F80,
4182                     RTLIB::ROUNDEVEN_F128,
4183                     RTLIB::ROUNDEVEN_PPCF128, Results);
4184     break;
4185   case ISD::FPOWI:
4186   case ISD::STRICT_FPOWI: {
4187     RTLIB::Libcall LC;
4188     switch (Node->getSimpleValueType(0).SimpleTy) {
4189     default: llvm_unreachable("Unexpected request for libcall!");
4190     case MVT::f32: LC = RTLIB::POWI_F32; break;
4191     case MVT::f64: LC = RTLIB::POWI_F64; break;
4192     case MVT::f80: LC = RTLIB::POWI_F80; break;
4193     case MVT::f128: LC = RTLIB::POWI_F128; break;
4194     case MVT::ppcf128: LC = RTLIB::POWI_PPCF128; break;
4195     }
4196     if (!TLI.getLibcallName(LC)) {
4197       // Some targets don't have a powi libcall; use pow instead.
4198       SDValue Exponent = DAG.getNode(ISD::SINT_TO_FP, SDLoc(Node),
4199                                      Node->getValueType(0),
4200                                      Node->getOperand(1));
4201       Results.push_back(DAG.getNode(ISD::FPOW, SDLoc(Node),
4202                                     Node->getValueType(0), Node->getOperand(0),
4203                                     Exponent));
4204       break;
4205     }
4206     ExpandFPLibCall(Node, RTLIB::POWI_F32, RTLIB::POWI_F64,
4207                     RTLIB::POWI_F80, RTLIB::POWI_F128,
4208                     RTLIB::POWI_PPCF128, Results);
4209     break;
4210   }
4211   case ISD::FPOW:
4212   case ISD::STRICT_FPOW:
4213     ExpandFPLibCall(Node, RTLIB::POW_F32, RTLIB::POW_F64, RTLIB::POW_F80,
4214                     RTLIB::POW_F128, RTLIB::POW_PPCF128, Results);
4215     break;
4216   case ISD::LROUND:
4217   case ISD::STRICT_LROUND:
4218     ExpandArgFPLibCall(Node, RTLIB::LROUND_F32,
4219                        RTLIB::LROUND_F64, RTLIB::LROUND_F80,
4220                        RTLIB::LROUND_F128,
4221                        RTLIB::LROUND_PPCF128, Results);
4222     break;
4223   case ISD::LLROUND:
4224   case ISD::STRICT_LLROUND:
4225     ExpandArgFPLibCall(Node, RTLIB::LLROUND_F32,
4226                        RTLIB::LLROUND_F64, RTLIB::LLROUND_F80,
4227                        RTLIB::LLROUND_F128,
4228                        RTLIB::LLROUND_PPCF128, Results);
4229     break;
4230   case ISD::LRINT:
4231   case ISD::STRICT_LRINT:
4232     ExpandArgFPLibCall(Node, RTLIB::LRINT_F32,
4233                        RTLIB::LRINT_F64, RTLIB::LRINT_F80,
4234                        RTLIB::LRINT_F128,
4235                        RTLIB::LRINT_PPCF128, Results);
4236     break;
4237   case ISD::LLRINT:
4238   case ISD::STRICT_LLRINT:
4239     ExpandArgFPLibCall(Node, RTLIB::LLRINT_F32,
4240                        RTLIB::LLRINT_F64, RTLIB::LLRINT_F80,
4241                        RTLIB::LLRINT_F128,
4242                        RTLIB::LLRINT_PPCF128, Results);
4243     break;
4244   case ISD::FDIV:
4245   case ISD::STRICT_FDIV:
4246     ExpandFPLibCall(Node, RTLIB::DIV_F32, RTLIB::DIV_F64,
4247                     RTLIB::DIV_F80, RTLIB::DIV_F128,
4248                     RTLIB::DIV_PPCF128, Results);
4249     break;
4250   case ISD::FREM:
4251   case ISD::STRICT_FREM:
4252     ExpandFPLibCall(Node, RTLIB::REM_F32, RTLIB::REM_F64,
4253                     RTLIB::REM_F80, RTLIB::REM_F128,
4254                     RTLIB::REM_PPCF128, Results);
4255     break;
4256   case ISD::FMA:
4257   case ISD::STRICT_FMA:
4258     ExpandFPLibCall(Node, RTLIB::FMA_F32, RTLIB::FMA_F64,
4259                     RTLIB::FMA_F80, RTLIB::FMA_F128,
4260                     RTLIB::FMA_PPCF128, Results);
4261     break;
4262   case ISD::FADD:
4263   case ISD::STRICT_FADD:
4264     ExpandFPLibCall(Node, RTLIB::ADD_F32, RTLIB::ADD_F64,
4265                     RTLIB::ADD_F80, RTLIB::ADD_F128,
4266                     RTLIB::ADD_PPCF128, Results);
4267     break;
4268   case ISD::FMUL:
4269   case ISD::STRICT_FMUL:
4270     ExpandFPLibCall(Node, RTLIB::MUL_F32, RTLIB::MUL_F64,
4271                     RTLIB::MUL_F80, RTLIB::MUL_F128,
4272                     RTLIB::MUL_PPCF128, Results);
4273     break;
4274   case ISD::FP16_TO_FP:
4275     if (Node->getValueType(0) == MVT::f32) {
4276       Results.push_back(ExpandLibCall(RTLIB::FPEXT_F16_F32, Node, false));
4277     }
4278     break;
4279   case ISD::STRICT_FP16_TO_FP: {
4280     if (Node->getValueType(0) == MVT::f32) {
4281       TargetLowering::MakeLibCallOptions CallOptions;
4282       std::pair<SDValue, SDValue> Tmp = TLI.makeLibCall(
4283           DAG, RTLIB::FPEXT_F16_F32, MVT::f32, Node->getOperand(1), CallOptions,
4284           SDLoc(Node), Node->getOperand(0));
4285       Results.push_back(Tmp.first);
4286       Results.push_back(Tmp.second);
4287     }
4288     break;
4289   }
4290   case ISD::FP_TO_FP16: {
4291     RTLIB::Libcall LC =
4292         RTLIB::getFPROUND(Node->getOperand(0).getValueType(), MVT::f16);
4293     assert(LC != RTLIB::UNKNOWN_LIBCALL && "Unable to expand fp_to_fp16");
4294     Results.push_back(ExpandLibCall(LC, Node, false));
4295     break;
4296   }
4297   case ISD::STRICT_FP_TO_FP16: {
4298     RTLIB::Libcall LC =
4299         RTLIB::getFPROUND(Node->getOperand(1).getValueType(), MVT::f16);
4300     assert(LC != RTLIB::UNKNOWN_LIBCALL &&
4301            "Unable to expand strict_fp_to_fp16");
4302     TargetLowering::MakeLibCallOptions CallOptions;
4303     std::pair<SDValue, SDValue> Tmp =
4304         TLI.makeLibCall(DAG, LC, Node->getValueType(0), Node->getOperand(1),
4305                         CallOptions, SDLoc(Node), Node->getOperand(0));
4306     Results.push_back(Tmp.first);
4307     Results.push_back(Tmp.second);
4308     break;
4309   }
4310   case ISD::FSUB:
4311   case ISD::STRICT_FSUB:
4312     ExpandFPLibCall(Node, RTLIB::SUB_F32, RTLIB::SUB_F64,
4313                     RTLIB::SUB_F80, RTLIB::SUB_F128,
4314                     RTLIB::SUB_PPCF128, Results);
4315     break;
4316   case ISD::SREM:
4317     Results.push_back(ExpandIntLibCall(Node, true,
4318                                        RTLIB::SREM_I8,
4319                                        RTLIB::SREM_I16, RTLIB::SREM_I32,
4320                                        RTLIB::SREM_I64, RTLIB::SREM_I128));
4321     break;
4322   case ISD::UREM:
4323     Results.push_back(ExpandIntLibCall(Node, false,
4324                                        RTLIB::UREM_I8,
4325                                        RTLIB::UREM_I16, RTLIB::UREM_I32,
4326                                        RTLIB::UREM_I64, RTLIB::UREM_I128));
4327     break;
4328   case ISD::SDIV:
4329     Results.push_back(ExpandIntLibCall(Node, true,
4330                                        RTLIB::SDIV_I8,
4331                                        RTLIB::SDIV_I16, RTLIB::SDIV_I32,
4332                                        RTLIB::SDIV_I64, RTLIB::SDIV_I128));
4333     break;
4334   case ISD::UDIV:
4335     Results.push_back(ExpandIntLibCall(Node, false,
4336                                        RTLIB::UDIV_I8,
4337                                        RTLIB::UDIV_I16, RTLIB::UDIV_I32,
4338                                        RTLIB::UDIV_I64, RTLIB::UDIV_I128));
4339     break;
4340   case ISD::SDIVREM:
4341   case ISD::UDIVREM:
4342     // Expand into divrem libcall
4343     ExpandDivRemLibCall(Node, Results);
4344     break;
4345   case ISD::MUL:
4346     Results.push_back(ExpandIntLibCall(Node, false,
4347                                        RTLIB::MUL_I8,
4348                                        RTLIB::MUL_I16, RTLIB::MUL_I32,
4349                                        RTLIB::MUL_I64, RTLIB::MUL_I128));
4350     break;
4351   case ISD::CTLZ_ZERO_UNDEF:
4352     switch (Node->getSimpleValueType(0).SimpleTy) {
4353     default:
4354       llvm_unreachable("LibCall explicitly requested, but not available");
4355     case MVT::i32:
4356       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I32, Node, false));
4357       break;
4358     case MVT::i64:
4359       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I64, Node, false));
4360       break;
4361     case MVT::i128:
4362       Results.push_back(ExpandLibCall(RTLIB::CTLZ_I128, Node, false));
4363       break;
4364     }
4365     break;
4366   }
4367 
4368   // Replace the original node with the legalized result.
4369   if (!Results.empty()) {
4370     LLVM_DEBUG(dbgs() << "Successfully converted node to libcall\n");
4371     ReplaceNode(Node, Results.data());
4372   } else
4373     LLVM_DEBUG(dbgs() << "Could not convert node to libcall\n");
4374 }
4375 
4376 // Determine the vector type to use in place of an original scalar element when
4377 // promoting equally sized vectors.
4378 static MVT getPromotedVectorElementType(const TargetLowering &TLI,
4379                                         MVT EltVT, MVT NewEltVT) {
4380   unsigned OldEltsPerNewElt = EltVT.getSizeInBits() / NewEltVT.getSizeInBits();
4381   MVT MidVT = MVT::getVectorVT(NewEltVT, OldEltsPerNewElt);
4382   assert(TLI.isTypeLegal(MidVT) && "unexpected");
4383   return MidVT;
4384 }
4385 
4386 void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
4387   LLVM_DEBUG(dbgs() << "Trying to promote node\n");
4388   SmallVector<SDValue, 8> Results;
4389   MVT OVT = Node->getSimpleValueType(0);
4390   if (Node->getOpcode() == ISD::UINT_TO_FP ||
4391       Node->getOpcode() == ISD::SINT_TO_FP ||
4392       Node->getOpcode() == ISD::SETCC ||
4393       Node->getOpcode() == ISD::EXTRACT_VECTOR_ELT ||
4394       Node->getOpcode() == ISD::INSERT_VECTOR_ELT) {
4395     OVT = Node->getOperand(0).getSimpleValueType();
4396   }
4397   if (Node->getOpcode() == ISD::STRICT_UINT_TO_FP ||
4398       Node->getOpcode() == ISD::STRICT_SINT_TO_FP)
4399     OVT = Node->getOperand(1).getSimpleValueType();
4400   if (Node->getOpcode() == ISD::BR_CC)
4401     OVT = Node->getOperand(2).getSimpleValueType();
4402   MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), OVT);
4403   SDLoc dl(Node);
4404   SDValue Tmp1, Tmp2, Tmp3;
4405   switch (Node->getOpcode()) {
4406   case ISD::CTTZ:
4407   case ISD::CTTZ_ZERO_UNDEF:
4408   case ISD::CTLZ:
4409   case ISD::CTLZ_ZERO_UNDEF:
4410   case ISD::CTPOP:
4411     // Zero extend the argument unless its cttz, then use any_extend.
4412     if (Node->getOpcode() == ISD::CTTZ ||
4413         Node->getOpcode() == ISD::CTTZ_ZERO_UNDEF)
4414       Tmp1 = DAG.getNode(ISD::ANY_EXTEND, dl, NVT, Node->getOperand(0));
4415     else
4416       Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4417 
4418     if (Node->getOpcode() == ISD::CTTZ) {
4419       // The count is the same in the promoted type except if the original
4420       // value was zero.  This can be handled by setting the bit just off
4421       // the top of the original type.
4422       auto TopBit = APInt::getOneBitSet(NVT.getSizeInBits(),
4423                                         OVT.getSizeInBits());
4424       Tmp1 = DAG.getNode(ISD::OR, dl, NVT, Tmp1,
4425                          DAG.getConstant(TopBit, dl, NVT));
4426     }
4427     // Perform the larger operation. For CTPOP and CTTZ_ZERO_UNDEF, this is
4428     // already the correct result.
4429     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4430     if (Node->getOpcode() == ISD::CTLZ ||
4431         Node->getOpcode() == ISD::CTLZ_ZERO_UNDEF) {
4432       // Tmp1 = Tmp1 - (sizeinbits(NVT) - sizeinbits(Old VT))
4433       Tmp1 = DAG.getNode(ISD::SUB, dl, NVT, Tmp1,
4434                           DAG.getConstant(NVT.getSizeInBits() -
4435                                           OVT.getSizeInBits(), dl, NVT));
4436     }
4437     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4438     break;
4439   case ISD::BITREVERSE:
4440   case ISD::BSWAP: {
4441     unsigned DiffBits = NVT.getSizeInBits() - OVT.getSizeInBits();
4442     Tmp1 = DAG.getNode(ISD::ZERO_EXTEND, dl, NVT, Node->getOperand(0));
4443     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4444     Tmp1 = DAG.getNode(
4445         ISD::SRL, dl, NVT, Tmp1,
4446         DAG.getConstant(DiffBits, dl,
4447                         TLI.getShiftAmountTy(NVT, DAG.getDataLayout())));
4448 
4449     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4450     break;
4451   }
4452   case ISD::FP_TO_UINT:
4453   case ISD::STRICT_FP_TO_UINT:
4454   case ISD::FP_TO_SINT:
4455   case ISD::STRICT_FP_TO_SINT:
4456     PromoteLegalFP_TO_INT(Node, dl, Results);
4457     break;
4458   case ISD::UINT_TO_FP:
4459   case ISD::STRICT_UINT_TO_FP:
4460   case ISD::SINT_TO_FP:
4461   case ISD::STRICT_SINT_TO_FP:
4462     PromoteLegalINT_TO_FP(Node, dl, Results);
4463     break;
4464   case ISD::VAARG: {
4465     SDValue Chain = Node->getOperand(0); // Get the chain.
4466     SDValue Ptr = Node->getOperand(1); // Get the pointer.
4467 
4468     unsigned TruncOp;
4469     if (OVT.isVector()) {
4470       TruncOp = ISD::BITCAST;
4471     } else {
4472       assert(OVT.isInteger()
4473         && "VAARG promotion is supported only for vectors or integer types");
4474       TruncOp = ISD::TRUNCATE;
4475     }
4476 
4477     // Perform the larger operation, then convert back
4478     Tmp1 = DAG.getVAArg(NVT, dl, Chain, Ptr, Node->getOperand(2),
4479              Node->getConstantOperandVal(3));
4480     Chain = Tmp1.getValue(1);
4481 
4482     Tmp2 = DAG.getNode(TruncOp, dl, OVT, Tmp1);
4483 
4484     // Modified the chain result - switch anything that used the old chain to
4485     // use the new one.
4486     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 0), Tmp2);
4487     DAG.ReplaceAllUsesOfValueWith(SDValue(Node, 1), Chain);
4488     if (UpdatedNodes) {
4489       UpdatedNodes->insert(Tmp2.getNode());
4490       UpdatedNodes->insert(Chain.getNode());
4491     }
4492     ReplacedNode(Node);
4493     break;
4494   }
4495   case ISD::MUL:
4496   case ISD::SDIV:
4497   case ISD::SREM:
4498   case ISD::UDIV:
4499   case ISD::UREM:
4500   case ISD::AND:
4501   case ISD::OR:
4502   case ISD::XOR: {
4503     unsigned ExtOp, TruncOp;
4504     if (OVT.isVector()) {
4505       ExtOp   = ISD::BITCAST;
4506       TruncOp = ISD::BITCAST;
4507     } else {
4508       assert(OVT.isInteger() && "Cannot promote logic operation");
4509 
4510       switch (Node->getOpcode()) {
4511       default:
4512         ExtOp = ISD::ANY_EXTEND;
4513         break;
4514       case ISD::SDIV:
4515       case ISD::SREM:
4516         ExtOp = ISD::SIGN_EXTEND;
4517         break;
4518       case ISD::UDIV:
4519       case ISD::UREM:
4520         ExtOp = ISD::ZERO_EXTEND;
4521         break;
4522       }
4523       TruncOp = ISD::TRUNCATE;
4524     }
4525     // Promote each of the values to the new type.
4526     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4527     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4528     // Perform the larger operation, then convert back
4529     Tmp1 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4530     Results.push_back(DAG.getNode(TruncOp, dl, OVT, Tmp1));
4531     break;
4532   }
4533   case ISD::UMUL_LOHI:
4534   case ISD::SMUL_LOHI: {
4535     // Promote to a multiply in a wider integer type.
4536     unsigned ExtOp = Node->getOpcode() == ISD::UMUL_LOHI ? ISD::ZERO_EXTEND
4537                                                          : ISD::SIGN_EXTEND;
4538     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4539     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4540     Tmp1 = DAG.getNode(ISD::MUL, dl, NVT, Tmp1, Tmp2);
4541 
4542     auto &DL = DAG.getDataLayout();
4543     unsigned OriginalSize = OVT.getScalarSizeInBits();
4544     Tmp2 = DAG.getNode(
4545         ISD::SRL, dl, NVT, Tmp1,
4546         DAG.getConstant(OriginalSize, dl, TLI.getScalarShiftAmountTy(DL, NVT)));
4547     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp1));
4548     Results.push_back(DAG.getNode(ISD::TRUNCATE, dl, OVT, Tmp2));
4549     break;
4550   }
4551   case ISD::SELECT: {
4552     unsigned ExtOp, TruncOp;
4553     if (Node->getValueType(0).isVector() ||
4554         Node->getValueType(0).getSizeInBits() == NVT.getSizeInBits()) {
4555       ExtOp   = ISD::BITCAST;
4556       TruncOp = ISD::BITCAST;
4557     } else if (Node->getValueType(0).isInteger()) {
4558       ExtOp   = ISD::ANY_EXTEND;
4559       TruncOp = ISD::TRUNCATE;
4560     } else {
4561       ExtOp   = ISD::FP_EXTEND;
4562       TruncOp = ISD::FP_ROUND;
4563     }
4564     Tmp1 = Node->getOperand(0);
4565     // Promote each of the values to the new type.
4566     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4567     Tmp3 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4568     // Perform the larger operation, then round down.
4569     Tmp1 = DAG.getSelect(dl, NVT, Tmp1, Tmp2, Tmp3);
4570     Tmp1->setFlags(Node->getFlags());
4571     if (TruncOp != ISD::FP_ROUND)
4572       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1);
4573     else
4574       Tmp1 = DAG.getNode(TruncOp, dl, Node->getValueType(0), Tmp1,
4575                          DAG.getIntPtrConstant(0, dl));
4576     Results.push_back(Tmp1);
4577     break;
4578   }
4579   case ISD::VECTOR_SHUFFLE: {
4580     ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Node)->getMask();
4581 
4582     // Cast the two input vectors.
4583     Tmp1 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(0));
4584     Tmp2 = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(1));
4585 
4586     // Convert the shuffle mask to the right # elements.
4587     Tmp1 = ShuffleWithNarrowerEltType(NVT, OVT, dl, Tmp1, Tmp2, Mask);
4588     Tmp1 = DAG.getNode(ISD::BITCAST, dl, OVT, Tmp1);
4589     Results.push_back(Tmp1);
4590     break;
4591   }
4592   case ISD::SETCC: {
4593     unsigned ExtOp = ISD::FP_EXTEND;
4594     if (NVT.isInteger()) {
4595       ISD::CondCode CCCode =
4596         cast<CondCodeSDNode>(Node->getOperand(2))->get();
4597       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4598     }
4599     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(0));
4600     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(1));
4601     Results.push_back(DAG.getNode(ISD::SETCC, dl, Node->getValueType(0), Tmp1,
4602                                   Tmp2, Node->getOperand(2), Node->getFlags()));
4603     break;
4604   }
4605   case ISD::BR_CC: {
4606     unsigned ExtOp = ISD::FP_EXTEND;
4607     if (NVT.isInteger()) {
4608       ISD::CondCode CCCode =
4609         cast<CondCodeSDNode>(Node->getOperand(1))->get();
4610       ExtOp = isSignedIntSetCC(CCCode) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
4611     }
4612     Tmp1 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(2));
4613     Tmp2 = DAG.getNode(ExtOp, dl, NVT, Node->getOperand(3));
4614     Results.push_back(DAG.getNode(ISD::BR_CC, dl, Node->getValueType(0),
4615                                   Node->getOperand(0), Node->getOperand(1),
4616                                   Tmp1, Tmp2, Node->getOperand(4)));
4617     break;
4618   }
4619   case ISD::FADD:
4620   case ISD::FSUB:
4621   case ISD::FMUL:
4622   case ISD::FDIV:
4623   case ISD::FREM:
4624   case ISD::FMINNUM:
4625   case ISD::FMAXNUM:
4626   case ISD::FPOW:
4627     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4628     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4629     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2,
4630                        Node->getFlags());
4631     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4632                                   Tmp3, DAG.getIntPtrConstant(0, dl)));
4633     break;
4634   case ISD::STRICT_FREM:
4635   case ISD::STRICT_FPOW:
4636     Tmp1 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4637                        {Node->getOperand(0), Node->getOperand(1)});
4638     Tmp2 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4639                        {Node->getOperand(0), Node->getOperand(2)});
4640     Tmp3 = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Tmp1.getValue(1),
4641                        Tmp2.getValue(1));
4642     Tmp1 = DAG.getNode(Node->getOpcode(), dl, {NVT, MVT::Other},
4643                        {Tmp3, Tmp1, Tmp2});
4644     Tmp1 = DAG.getNode(ISD::STRICT_FP_ROUND, dl, {OVT, MVT::Other},
4645                        {Tmp1.getValue(1), Tmp1, DAG.getIntPtrConstant(0, dl)});
4646     Results.push_back(Tmp1);
4647     Results.push_back(Tmp1.getValue(1));
4648     break;
4649   case ISD::FMA:
4650     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4651     Tmp2 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(1));
4652     Tmp3 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(2));
4653     Results.push_back(
4654         DAG.getNode(ISD::FP_ROUND, dl, OVT,
4655                     DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2, Tmp3),
4656                     DAG.getIntPtrConstant(0, dl)));
4657     break;
4658   case ISD::FCOPYSIGN:
4659   case ISD::FPOWI: {
4660     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4661     Tmp2 = Node->getOperand(1);
4662     Tmp3 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1, Tmp2);
4663 
4664     // fcopysign doesn't change anything but the sign bit, so
4665     //   (fp_round (fcopysign (fpext a), b))
4666     // is as precise as
4667     //   (fp_round (fpext a))
4668     // which is a no-op. Mark it as a TRUNCating FP_ROUND.
4669     const bool isTrunc = (Node->getOpcode() == ISD::FCOPYSIGN);
4670     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4671                                   Tmp3, DAG.getIntPtrConstant(isTrunc, dl)));
4672     break;
4673   }
4674   case ISD::FFLOOR:
4675   case ISD::FCEIL:
4676   case ISD::FRINT:
4677   case ISD::FNEARBYINT:
4678   case ISD::FROUND:
4679   case ISD::FROUNDEVEN:
4680   case ISD::FTRUNC:
4681   case ISD::FNEG:
4682   case ISD::FSQRT:
4683   case ISD::FSIN:
4684   case ISD::FCOS:
4685   case ISD::FLOG:
4686   case ISD::FLOG2:
4687   case ISD::FLOG10:
4688   case ISD::FABS:
4689   case ISD::FEXP:
4690   case ISD::FEXP2:
4691     Tmp1 = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(0));
4692     Tmp2 = DAG.getNode(Node->getOpcode(), dl, NVT, Tmp1);
4693     Results.push_back(DAG.getNode(ISD::FP_ROUND, dl, OVT,
4694                                   Tmp2, DAG.getIntPtrConstant(0, dl)));
4695     break;
4696   case ISD::STRICT_FFLOOR:
4697   case ISD::STRICT_FCEIL:
4698   case ISD::STRICT_FSIN:
4699   case ISD::STRICT_FCOS:
4700   case ISD::STRICT_FLOG:
4701   case ISD::STRICT_FLOG10:
4702   case ISD::STRICT_FEXP:
4703     Tmp1 = DAG.getNode(ISD::STRICT_FP_EXTEND, dl, {NVT, MVT::Other},
4704                        {Node->getOperand(0), Node->getOperand(1)});
4705     Tmp2 = DAG.getNode(Node->getOpcode(), dl, {NVT, MVT::Other},
4706                        {Tmp1.getValue(1), Tmp1});
4707     Tmp3 = DAG.getNode(ISD::STRICT_FP_ROUND, dl, {OVT, MVT::Other},
4708                        {Tmp2.getValue(1), Tmp2, DAG.getIntPtrConstant(0, dl)});
4709     Results.push_back(Tmp3);
4710     Results.push_back(Tmp3.getValue(1));
4711     break;
4712   case ISD::BUILD_VECTOR: {
4713     MVT EltVT = OVT.getVectorElementType();
4714     MVT NewEltVT = NVT.getVectorElementType();
4715 
4716     // Handle bitcasts to a different vector type with the same total bit size
4717     //
4718     // e.g. v2i64 = build_vector i64:x, i64:y => v4i32
4719     //  =>
4720     //  v4i32 = concat_vectors (v2i32 (bitcast i64:x)), (v2i32 (bitcast i64:y))
4721 
4722     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4723            "Invalid promote type for build_vector");
4724     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4725 
4726     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4727 
4728     SmallVector<SDValue, 8> NewOps;
4729     for (unsigned I = 0, E = Node->getNumOperands(); I != E; ++I) {
4730       SDValue Op = Node->getOperand(I);
4731       NewOps.push_back(DAG.getNode(ISD::BITCAST, SDLoc(Op), MidVT, Op));
4732     }
4733 
4734     SDLoc SL(Node);
4735     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewOps);
4736     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4737     Results.push_back(CvtVec);
4738     break;
4739   }
4740   case ISD::EXTRACT_VECTOR_ELT: {
4741     MVT EltVT = OVT.getVectorElementType();
4742     MVT NewEltVT = NVT.getVectorElementType();
4743 
4744     // Handle bitcasts to a different vector type with the same total bit size.
4745     //
4746     // e.g. v2i64 = extract_vector_elt x:v2i64, y:i32
4747     //  =>
4748     //  v4i32:castx = bitcast x:v2i64
4749     //
4750     // i64 = bitcast
4751     //   (v2i32 build_vector (i32 (extract_vector_elt castx, (2 * y))),
4752     //                       (i32 (extract_vector_elt castx, (2 * y + 1)))
4753     //
4754 
4755     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4756            "Invalid promote type for extract_vector_elt");
4757     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4758 
4759     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4760     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4761 
4762     SDValue Idx = Node->getOperand(1);
4763     EVT IdxVT = Idx.getValueType();
4764     SDLoc SL(Node);
4765     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SL, IdxVT);
4766     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4767 
4768     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4769 
4770     SmallVector<SDValue, 8> NewOps;
4771     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4772       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4773       SDValue TmpIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4774 
4775       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4776                                 CastVec, TmpIdx);
4777       NewOps.push_back(Elt);
4778     }
4779 
4780     SDValue NewVec = DAG.getBuildVector(MidVT, SL, NewOps);
4781     Results.push_back(DAG.getNode(ISD::BITCAST, SL, EltVT, NewVec));
4782     break;
4783   }
4784   case ISD::INSERT_VECTOR_ELT: {
4785     MVT EltVT = OVT.getVectorElementType();
4786     MVT NewEltVT = NVT.getVectorElementType();
4787 
4788     // Handle bitcasts to a different vector type with the same total bit size
4789     //
4790     // e.g. v2i64 = insert_vector_elt x:v2i64, y:i64, z:i32
4791     //  =>
4792     //  v4i32:castx = bitcast x:v2i64
4793     //  v2i32:casty = bitcast y:i64
4794     //
4795     // v2i64 = bitcast
4796     //   (v4i32 insert_vector_elt
4797     //       (v4i32 insert_vector_elt v4i32:castx,
4798     //                                (extract_vector_elt casty, 0), 2 * z),
4799     //        (extract_vector_elt casty, 1), (2 * z + 1))
4800 
4801     assert(NVT.isVector() && OVT.getSizeInBits() == NVT.getSizeInBits() &&
4802            "Invalid promote type for insert_vector_elt");
4803     assert(NewEltVT.bitsLT(EltVT) && "not handled");
4804 
4805     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4806     unsigned NewEltsPerOldElt = MidVT.getVectorNumElements();
4807 
4808     SDValue Val = Node->getOperand(1);
4809     SDValue Idx = Node->getOperand(2);
4810     EVT IdxVT = Idx.getValueType();
4811     SDLoc SL(Node);
4812 
4813     SDValue Factor = DAG.getConstant(NewEltsPerOldElt, SDLoc(), IdxVT);
4814     SDValue NewBaseIdx = DAG.getNode(ISD::MUL, SL, IdxVT, Idx, Factor);
4815 
4816     SDValue CastVec = DAG.getNode(ISD::BITCAST, SL, NVT, Node->getOperand(0));
4817     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4818 
4819     SDValue NewVec = CastVec;
4820     for (unsigned I = 0; I < NewEltsPerOldElt; ++I) {
4821       SDValue IdxOffset = DAG.getConstant(I, SL, IdxVT);
4822       SDValue InEltIdx = DAG.getNode(ISD::ADD, SL, IdxVT, NewBaseIdx, IdxOffset);
4823 
4824       SDValue Elt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, NewEltVT,
4825                                 CastVal, IdxOffset);
4826 
4827       NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, SL, NVT,
4828                            NewVec, Elt, InEltIdx);
4829     }
4830 
4831     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewVec));
4832     break;
4833   }
4834   case ISD::SCALAR_TO_VECTOR: {
4835     MVT EltVT = OVT.getVectorElementType();
4836     MVT NewEltVT = NVT.getVectorElementType();
4837 
4838     // Handle bitcasts to different vector type with the same total bit size.
4839     //
4840     // e.g. v2i64 = scalar_to_vector x:i64
4841     //   =>
4842     //  concat_vectors (v2i32 bitcast x:i64), (v2i32 undef)
4843     //
4844 
4845     MVT MidVT = getPromotedVectorElementType(TLI, EltVT, NewEltVT);
4846     SDValue Val = Node->getOperand(0);
4847     SDLoc SL(Node);
4848 
4849     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, MidVT, Val);
4850     SDValue Undef = DAG.getUNDEF(MidVT);
4851 
4852     SmallVector<SDValue, 8> NewElts;
4853     NewElts.push_back(CastVal);
4854     for (unsigned I = 1, NElts = OVT.getVectorNumElements(); I != NElts; ++I)
4855       NewElts.push_back(Undef);
4856 
4857     SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SL, NVT, NewElts);
4858     SDValue CvtVec = DAG.getNode(ISD::BITCAST, SL, OVT, Concat);
4859     Results.push_back(CvtVec);
4860     break;
4861   }
4862   case ISD::ATOMIC_SWAP: {
4863     AtomicSDNode *AM = cast<AtomicSDNode>(Node);
4864     SDLoc SL(Node);
4865     SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, NVT, AM->getVal());
4866     assert(NVT.getSizeInBits() == OVT.getSizeInBits() &&
4867            "unexpected promotion type");
4868     assert(AM->getMemoryVT().getSizeInBits() == NVT.getSizeInBits() &&
4869            "unexpected atomic_swap with illegal type");
4870 
4871     SDValue NewAtomic
4872       = DAG.getAtomic(ISD::ATOMIC_SWAP, SL, NVT,
4873                       DAG.getVTList(NVT, MVT::Other),
4874                       { AM->getChain(), AM->getBasePtr(), CastVal },
4875                       AM->getMemOperand());
4876     Results.push_back(DAG.getNode(ISD::BITCAST, SL, OVT, NewAtomic));
4877     Results.push_back(NewAtomic.getValue(1));
4878     break;
4879   }
4880   }
4881 
4882   // Replace the original node with the legalized result.
4883   if (!Results.empty()) {
4884     LLVM_DEBUG(dbgs() << "Successfully promoted node\n");
4885     ReplaceNode(Node, Results.data());
4886   } else
4887     LLVM_DEBUG(dbgs() << "Could not promote node\n");
4888 }
4889 
4890 /// This is the entry point for the file.
4891 void SelectionDAG::Legalize() {
4892   AssignTopologicalOrder();
4893 
4894   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4895   // Use a delete listener to remove nodes which were deleted during
4896   // legalization from LegalizeNodes. This is needed to handle the situation
4897   // where a new node is allocated by the object pool to the same address of a
4898   // previously deleted node.
4899   DAGNodeDeletedListener DeleteListener(
4900       *this,
4901       [&LegalizedNodes](SDNode *N, SDNode *E) { LegalizedNodes.erase(N); });
4902 
4903   SelectionDAGLegalize Legalizer(*this, LegalizedNodes);
4904 
4905   // Visit all the nodes. We start in topological order, so that we see
4906   // nodes with their original operands intact. Legalization can produce
4907   // new nodes which may themselves need to be legalized. Iterate until all
4908   // nodes have been legalized.
4909   while (true) {
4910     bool AnyLegalized = false;
4911     for (auto NI = allnodes_end(); NI != allnodes_begin();) {
4912       --NI;
4913 
4914       SDNode *N = &*NI;
4915       if (N->use_empty() && N != getRoot().getNode()) {
4916         ++NI;
4917         DeleteNode(N);
4918         continue;
4919       }
4920 
4921       if (LegalizedNodes.insert(N).second) {
4922         AnyLegalized = true;
4923         Legalizer.LegalizeOp(N);
4924 
4925         if (N->use_empty() && N != getRoot().getNode()) {
4926           ++NI;
4927           DeleteNode(N);
4928         }
4929       }
4930     }
4931     if (!AnyLegalized)
4932       break;
4933 
4934   }
4935 
4936   // Remove dead nodes now.
4937   RemoveDeadNodes();
4938 }
4939 
4940 bool SelectionDAG::LegalizeOp(SDNode *N,
4941                               SmallSetVector<SDNode *, 16> &UpdatedNodes) {
4942   SmallPtrSet<SDNode *, 16> LegalizedNodes;
4943   SelectionDAGLegalize Legalizer(*this, LegalizedNodes, &UpdatedNodes);
4944 
4945   // Directly insert the node in question, and legalize it. This will recurse
4946   // as needed through operands.
4947   LegalizedNodes.insert(N);
4948   Legalizer.LegalizeOp(N);
4949 
4950   return LegalizedNodes.count(N);
4951 }
4952